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Terebellides africana Augener, 1918 stat. prom. Figures 2A, 3���7, 11A, 37; Tables 1, 2 Terebellides Stroemi var. africana Augener, 1918. Augener (1918): 555 ���560, Plate 7, fig. 245, text fig. 96. Material examined. Type material. Two syntypes (ZMH V1709, ZMH V1712) (Table 1); lectotype: V1709 (female with intra-coelomic oocytes); paralectotype: V1712 (see Discussion). Non-type material. Seven specimens (NHMD-231436, NHMD-231441, NHMD-231453, NHMD-231455, NHMD-231458); Atlantide and Galathea expeditions (Kirkegaard, 1959) (Table 1). Diagnosis. Body large (20���30 mm in length). Branchial anterior lobe present; posterior ventral lobes much smaller than dorsal ones, without terminal filament and emerging after fusion line of dorsal ones. TC1 notopodia and notochaetae as long as following. Thoracic neurochaetae with rostrum / capitium length about 3/1, and capitium with a first row of 3(4) medium-sized teeth, followed by progressively smaller teeth. Description of lectotype Measurements and general body features. Complete specimen, 32 mm long and 3.0 mm wide (Fig. 2A, 3 A���C), body tapering posteriorly, with segments increasingly shorter and crowded towards pygidium. Prostomium compact, large tentacular membrane with typical buccal tentacles with expanded tips. SGI forming an expanded lower lip below tentacular membrane (Fig. 3 E���F). Lateral lappets not conspicuous on SGIII���VII (TC1���5), larger in SGIII���V, with low dorsal projections in TC1���3 (Fig. 5A); TC2 dorsally elevated in relation to TC1 and TC3 (Fig. 2A, 5A). Oval-shaped glandular region in CH 3 not observed. Branchiae. Branchiae arising as single structure from SGIII, with a single, short, stalked, mid-dorsal branch, typically comma-shaped and reaching TC3 (Fig. 2A, 3 A���C). A short anterior lobe (see below) and two pairs of pos- terior lobes: one pair dorsal (upper), with lobes 1+2 fused along most of their length, one pair ventral (lower), with lobes 3+4 much shorter than dorsal ones, not fused together, near distal end and after a long fusion line of dorsal ones. Anterior projection of dorsal lobes (lobe 5) short, about �� of dorsal lobes��� length (Fig. 2A, 3 C���D, 4B). Pointed projection of posterior region of both upper and lower lobes short, a bit longer in lower ones but never forming a long terminal filament. Branchial lamellae with well-developed ciliary rows and ciliated papillae on lamellar outer edge (Fig. 5B). Thorax. Eighteen pairs of notopodia (SGIII���XX), that of TC1 about as long as following ones (Fig. 3E, 5A), with dorsal projection; notochaetae as simple capillaries as long as following ones. TC2 and TC3 with dorsal projection similar to TC1 (Fig. 5A, C). Notopodia of TC2 shifted dorsally in some specimens (Fig. 5A). Neuropodia as sessile pinnules from TC6 (SGVIII) to pygidium, with uncini in single rows starting from TC7 (SGIX) throughout. First neuropodia at TC6, with five sharply bent, acute tipped, geniculate chaetae in left torus (Fig. 6 A���B); right side torus lost, presumably removed by H. Augener (Fig. 3C). From TC7, neuropodia with up to 18���22 uncini per torus in one row, with long shafted denticulate hooks, rostrum about three times longer than capitium, with three large teeth above main fang, and surmounted by an upper crest of several smaller denticles (Fig. 7 A���C), dorsalmost hooks in anteriormost uncinigers showing a very short rostrum and a less angled capitium in relation to chaetal main axis, resembling aciculae (Fig. 6 C���D). Abdomen. Abdomen as long as thorax. Thirty-two to thirty-four pairs of neuropodia as erect pinnules with about 25���30 uncini per torus; uncini with about five teeth above main fang, surmounted by a upper crest of 2 teeth and a variable number of smaller denticles (?) (see Fig. 2E in Augener, 1918). Other body features. Single, well-developed nephridial papilla behind TC1 notopodia and nephridial openings dorsal to TC4���5 notopodium (Fig. 5A, C). Pygidium as blunt, funnel-like depression. Methyl green staining pattern. Striped through the entire thorax; pattern 7 of Sch��ller & Hutchings (2010) (Fig. 37). Variability. Type specimens differing in size (paralectotype: 22.0 mm long, 2.0 mm wide), but showing no significant differences in relevant morphological characters. Branchiae clearly smaller in lectotype than in non-type specimens identified by Kirkegaard (1959), likely due to a longer preservation in alcohol. Type locality. Equatorial Guinea; 0���30 m depth (Table 1). The location corresponds to the lectotype (V-1709), while Augener (1918) simply refers to ���West Africa��� for the paralectotype (V-1712). Distribution and bathymetry. The revision of material from the Atlantide expedition, originally identified as T. stroemii by Kirkegaard (1959), expands the distribution of T. africana stat. prom. to the Gold Coast and Nigeria, from 17 to 66 m depth (Fig. 11A). The specimen NHMD-231441, collected during the Galathea expedition (75 m depth, off Angola), mostly agrees with the diagnosis of T. africana stat. prom., but its very poor condition prevented fully confirming its identity. The specimen NHMD-231455 (Fig. 4C) shows two filiform structures protruding dorsally from TC3 that might correspond to a parasitic copepod. Nomenclatural note. Following Alonso-Zarazaga (2007), the term stat. prom. (Lat. status promotus; Eng. promoted status) is used here to qualify T. africana instead of the classical stat. nov. (Lat. status novus; Eng. new status) for referring to the rising of a subspecies (meaning of ���variety��� following the International Code for Zoological Nomenclature-ICZN, article 45.6.4.) to the species rank. This author also proposed stat. dem. (Lat. status demotes; Eng. demoted status) instead of stat. nov. (i.e., upgrading an infrasubspecific entity to specific or subspecific status, ICZN, article 16A). Remarks. Even though type specimens were not examined under SEM to avoid damage, this species is clearly distinguished from the other described here due to its large body size, a TC1 similar in size to following thoracic notopodia, and branchiae with very short ventral lobes emerging close to the distal end of the dorsal ones. Terebellides africana stat. prom. resembles T. stroemii as redescribed by Parapar & Hutchings (2015) in size and general body shape, typical comma-shaped branchiae, and appearance and size of TC1, and mostly differs in branchial features: 1) ventral and anterior lobes clearly smaller, the former showing a different position, and 2) lobes bearing ciliated papillae (Fig. 5 A���B) (absent in T. stroemii, Parapar & Hutchings, 2015: Fig. 6 E���F). Terebellides africana stat. prom. resembles T. stroemii sensu Caullery (1944) from Indonesia (St. 271 of Siboga Expedition) in branchiae size and shape, which reach TC3 (Caullery, 1944: Fig. 147A). However, their ventral posterior lobes are much different, and resemble those of a specimen from St. 311 (Caullery, 1944: Fig. 148A) that has also larger anterior branchial lobes. Therefore, we suspect that each of them might correspond to undescribed species. Rullier (1964a) reported T. stroemii from Cameroon, near the type locality of T. africana stat. prom. (Equatorial Guinea), which were not assigned to the variety africana due to the shape of TC6 geniculate chaetae (not illustrated in his paper). Even though we were not able to examine this material, deposited in the Mus��um national d���Histoire naturelle (Paris), it seems it does not correspond to any of the species described here. Two species described here, T. kirkegaardi sp. nov. and T. longiseta sp. nov., are geographically close to T. africana stat. prom., but they clearly differ in the shape of TC6 geniculate chaetae. Terebellides persiae Parapar, Moreira, Gil & Martin, 2016 overall resembles T. africana stat. prom., but differs in having much larger branchiae (particularly the anterior lobe) and a characteristic thoracic dorsal hump (cfr. Fig. 2B & 3A in Parapar et al., 2016b) absent in T. africana stat. prom. Terebellides parvus Sol��s-Weiss et al., 1991 (Sol��s-Weiss et al., 1991: Fig. 2a) has also similar branchiae, but differs by having fewer abdominal chaetigers (25 vs. 32���34 in T. africana stat. prom.). The relative size and position of the postero-ventral branchial lobes in relation to the dorsal ones in T. africana stat. prom. resembles those of T. mediterranea Parapar, Mikac & Fiege, 2013, T. guangdongensis Zhang & Hutchings, 2018 and T. yangi Zhang & Hutchings, 2018. However, T. mediterranea has much larger ventral lobes, a more developed branchial stem, and a larger TC1 with longer notochaetae; T. guangdongensis shows smaller anterior branchial lobes and a very small TC1, and T. yangi clearly differs in having much-developed anterior lobes, similar to those of T. longiseta sp. nov. (see below). Terebellides africana stat. prom. resembles T. augeneri sp. nov., but differs in body size (22���32 mm vs. 7���19 mm in T. augeneri sp. nov.) and in the position of the branchial ventral lobes (arising from the base of the dorsal ones in T. augeneri sp. nov.). Two more species here described occur in shallow waters: T. congolana sp. nov. and T. kirkegaardi sp. nov. The former resembles T. africana stat. prom. in body size and shape and in the position of branchial ventral lobes but differs in having much longer branchial dorsal lobes that reach TC6 and a TC1 notopodium proportionally larger compared to thorax size. On the other hand, T. kirkegaardi sp. nov. differs from T. africana stat. prom. in having a distinctly smaller body and branchiae with a very long branchial stem, an anterior lobe about half the length of posterior ones, and ventral lobes originating from the base of dorsal ones., Published as part of Parapar, Julio, Martin, Daniel & Moreira, Juan, 2020, On the diversity of Terebellides (Annelida, Trichobranchidae) in West Africa, seven new species and the redescription of T. africana Augener, 1918 stat. prom., pp. 1-61 in Zootaxa 4771 (1) on pages 7-13, DOI: 10.11646/zootaxa.4771.1.1, http://zenodo.org/record/3798452, {"references":["Augener, H. (1918) Polychaeta. In: Michaelsen, W. (Ed.), Beitrage zur Kenntnis der Meeresfauna Westafrikas 2. L. Friederichsen, Hamburg, pp. 67 - 625.","Kirkegaard, J. B. (1959) The polychaete fauna of West Africa. Part I. Sedentary species. Atlantide Report. Scientific Results of the Danish expedition to the coasts of tropical West Africa, 1945 - 1946, 5, 7 - 117.","Schuller, M. & Hutchings, P. A. (2010) New insights in the taxonomy of Trichobranchidae (Polychaeta) with the description of a new Terebellides from Australia. Zootaxa, 2395 (1), 1 - 16. https: // doi. org / 10.11646 / zootaxa. 2395.1.1","Alonso-Zarazaga, M. A. (2007) Acalyptini C. G. Thomson 1859, correct name for a tribe in Curculioninae (Coleoptera: Curculionidae) and a comment on nomenclatural terminology. The Coleopterists Bulletin, 61 (4), 559. https: // doi. org / 10.1649 / 0010 - 065 X (2007) 61 [559: ACGTCN] 2.0. CO; 2","Parapar, J. & Hutchings, P. (2015) Redescription of Terebellides stroemii (Polychaeta, Trichobranchidae) and designation of a neotype. Journal of the Marine Biological Association of United Kingdom, 95, 323 - 337. https: // doi. org / 10.1017 / S 0025315414000903","Caullery, M. (1944) Polychetes Sedentaires de l'Expedition du Siboga: Ariciidae, Spionidae, Chaetopteridae, Chlorhaemidae, Opheliidae, Oweniidae, Sabellariidae, Sternaspidae, Amphictenidae, Ampharetidae, Terebellidae. Siboga Expeditie, Leiden, 24 (2 bis), 1 - 204.","Rullier, F. (1964 a) Contribution a la faune des Annelides Polychetes du Cameroun. Bulletin de l'Institut francais d'Afrique noire, 26, 1071 - 1102.","Parapar, J., Moreira, J., Gil, J. & Martin, D. (2016 b) A new species of the genus Terebellides (Polychaeta, Trichobranchidae) from the Iranian coast. Zootaxa, 4117 (3), 321 - 340. https: // doi. org / 10.11646 / zootaxa. 4117.3.2","Solis-Weiss, V., Fauchald, K. & Blankestein, A. (1991) Trichobranchidae (Polychaeta) from shallow warm water areas in the Western Atlantic Ocean. Proceedings of the Biological Society of Washington, 104 (1), 147 - 158.","Parapar, J., Mikac, B. & Fiege, D. (2013) Diversity of the genus Terebellides (Polychaeta: Trichobranchidae) in the Adriatic Sea with the description of a new species. Zootaxa, 3691 (3), 333 - 350. https: // doi. org / 10.11646 / zootaxa. 3691.3.3","Zhang, J. & Hutchings, P. (2018) Taxonomy and distribution of Terebellides (Polychaeta: Trichobranchidae) in the northern South China Sea, with description of three new species. Zootaxa, 4377 (3), 387 - 411. https: // doi. org / 10.11646 / zootaxa. 4377.3.4"]}

Genus Terebellides Sars, 1835 emended by Sch��ller & Hutchings, 2013 Type species. Terebellides stroemii Sars, 1835, redescribed in Parapar & Hutchings (2015), Published as part of Parapar, Julio, Martin, Daniel & Moreira, Juan, 2020, On the diversity of Terebellides (Annelida, Trichobranchidae) in West Africa, seven new species and the redescription of T. africana Augener, 1918 stat. prom., pp. 1-61 in Zootaxa 4771 (1) on page 7, DOI: 10.11646/zootaxa.4771.1.1, http://zenodo.org/record/3798452, {"references":["Sars, M. (1835) Beskrivelser og iagttagelser over nogle maerkelige eller nye i Havet ved den Bergenske Kyst levende Dyr af Polypernes, Acephalernes, Radiaternes, Annelidernes og Molluskernes Classer, med en kort Oversigt over de hidtil af Forfatteren sammesteds fundne Arter og deres Forekommen. Thorstein Hallagers Forlag hos Chr. Dahl, R. S., Bergen, 81 pp. https: // doi. org / 10.5962 / bhl. title. 13017","Schuller, M. & Hutchings, P. A. (2013) New species of Terebellides (Polychaeta: Trichobranchidae) from deep Southern Ocean. Zootaxa, 3619 (1), 1 - 45. https: // doi. org / 10.11646 / zootaxa. 3619.1.1","Parapar, J. & Hutchings, P. (2015) Redescription of Terebellides stroemii (Polychaeta, Trichobranchidae) and designation of a neotype. Journal of the Marine Biological Association of United Kingdom, 95, 323 - 337. https: // doi. org / 10.1017 / S 0025315414000903"]}

Terebellides sp. 2 Figures 11D, 35 C���D; Tables 1, 2 Material examined. One specimen (NHMD-231449, Table 1). Description. Complete specimen, not well-preserved, 11 mm long and 1.0 mm wide (Fig. 35 C���D), mature female, with numerous intra-coelomic oocytes. Anterior thoracic segments (TC1���5) ventrally white. General bran- chial structure not well defined because the state of preservation, not clearly corresponding to any species described in this work. Distribution and bathymetry. South Africa (off Cape Point); 110 m depth (Fig. 11D; Table 1). Remarks. Terebellides stroemii was widely reported by Day (1967) along the coasts of South Africa, including Cape Point, nearby where this specimen was collected. This author provided a brief description of his material but did not mention explicitly where it was collected. However, these specimens clearly differ from Terebellides sp. 2 at least in two characters: larger body size (up to 70 mm) and a much larger shelf-like mouth lower lip (Day, 1967: Fig. 36.1. f-g). Moreover, Day���s drawings show well-developed anterior and posterior branchial lobes, posterior ventral ones being shorter than dorsal ones and not fused to the latter (although reported as ���partially fused��� in the description); such drawings illustrate the TC6 geniculate chaetae and the thoracic and abdominal uncini but, unfortunately, these characters could not be examined in detail in our specimen without causing irreversible damage. This set of characters does not allow us to assign this specimen neither to any of the above described species nor to Day���s material., Published as part of Parapar, Julio, Martin, Daniel & Moreira, Juan, 2020, On the diversity of Terebellides (Annelida, Trichobranchidae) in West Africa, seven new species and the redescription of T. africana Augener, 1918 stat. prom., pp. 1-61 in Zootaxa 4771 (1) on page 53, DOI: 10.11646/zootaxa.4771.1.1, http://zenodo.org/record/3798452, {"references":["Day, J. H. (1967) A monograph on the Polychaeta of Southern Africa. Part 2: Sedentaria. The British Museum of Natural History, 656, 459 - 878. https: // doi. org / 10.5962 / bhl. title. 8596"]}

Terebellides longiseta sp. nov. Figures 11C, 21B, 25−27, 37; Tables 1, 2 urn:lsid:zoobank.org:act: 33AEE210-CA77-488F-A43B-2FDC23375CBE Material examined. Type material. Holotype (NHMD-231459); paratypes: five specimens (NHMD-231437, NHMD-231448 and NHMD-636926). Non-type material. One specimen (MNCN 16.01 /18591, Table 1). Diagnosis. Body medium/big sized (up to 21 mm in length). Anterior branchial lobe large; posterior ventral lobes thinner than dorsal ones, with long terminal filament, directly emerging from branchial stem. TC1 about as long as following ones; all thoracic notochaetae very long and numerous, with rostrum vs capitium length of about 1/1, and capitium with a first row of 3 big teeth followed by much smaller ones. Description based on holotype Measurements and general body features. Incomplete specimen, broken at TC10; 8.0 mm long and 3.5 mm wide (Fig. 21B, 25A). Prostomium compact; large tentacular membrane surrounding mouth; buccal tentacles lost. SGI as an expanded structure below tentacular membrane. Lateral lappets on SG3–6 (TC1–4), especially large in SG3 (TC1) forming a fan-shaped antero-dorsal expansion (Fig. 25 B–C, arrow). Branchiae. Branchiae arising as single structure from SG3, with a single stalked mid-dorsal branch having one pair of dorsal (upper) lobes (1+2), not fused along their length, and one pair of ventral (lower) lobes (3+4) of similar length but much thinner, neither fused together nor to dorsal ones (Fig. 21B, 25B, D). Anterior lobe (lobe 5) well developed, triangular, about half to 1/3 length of posterior dorsal lobes (Fig. 25C). Pointed projection of both upper and lower posterior lobes much longer in ventral ones, becoming a long terminal filament (Fig. 25B, D, 26 B−C). Both sides of branchial lamellae with several parallel rows of cilia and low ciliated tufts, giving a zig-zag appearance to outer edge of dorsal posterior lobe branchial lamellae under stereomicroscope (Fig. 25B, D). Thorax. Incomplete, with ten pairs of notopodia from SG3 to SG12 (TC1 to TC10). TC1 notopodia well developed, as long as subsequent ones (Fig. 25 B−C, 26A). All notochaetae simple capillaries with textured surface, very long (near body width at same level) and numerous (12–15 per notopodium). Neuropodia as sessile pinnules from TC6 (SG8), with uncini in single rows starting from TC7 (SG9) throughout. First neuropodia (TC6/TU1) with 8–9 sharply bent, acute-tipped, geniculate chaetae, having minute teeth forming a capitium visible under SEM. From TC7, neuropodia with about 20–25 partially extruded uncini per torus in one row, with long shafted denticulate hooks, rostrum about same length as capitium, with three big teeth above main fang surmounted by an upper crest of several much smaller denticles (Fig. 27 A−B). Abdomen. Not present in holotype (see below). Other features. Nephridial papilla and nephridial openings not seen (see below). Methyl green staining pattern. Not determined; only one complete specimen available but ventrally contract- ed. Variability. Only one complete specimen (NHMD-231448), 21 mm long, 1.5 mm wide, with 30 abdominal chaetigers. Specimen NHMD-636926 similar to holotype, with a conspicuous fan-shaped antero-dorsal expansion, branchiae with only ventral posterior lobes, very thin and with about 25 lamellae each, and nephridial openings in TN4−5. One specimen from NHMD-231448 with a scar caused by a copepod attachment near to TC1 notopodium; another complete specimen from same vial (with about 30 abdominal segments) with neuropodia as erect pinnules and about 25–30 uncini per torus having uncini with four teeth above main fang surmounted by one/two smaller ones and an upper crest of smaller teeth (Fig. 27 C–D). Pygidium blunt, as funnel-like depression. Specimens from NHMD-231437 badly preserved, but characteristically long, with abundant notochaetae on last half of thorax and branchiae with terminal filament in posterior ventral lobes and lamellae border conspicuously sinuous, similar to holotype. Type locality. Equatorial Guinea; 260–650 m depth (Table 1). Distribution and bathymetry. From Equatorial Guinea to South Angola in SW Africa; 235–650 m depth (Fig. 11C; Table 1). Etymology. The epithet refers to the very long and numerous chaetae present in thoracic notopodia. Remarks. The conspicuous, long thoracic notochaetae are the most distinctive character of T. longiseta sp. nov. Other species with long notochaetae are Terebellides klemani Kinberg, 1867 (Brazil) and Terebellides irinae Gagaev, 2009 (Arctic Basin), but they are thinner and fewer, 2–4 in T. klemani, and 5–10 in T. irinae. In addition, T. klemani bears TC1 notochaetae shorter than those of following chaetigers; the branchiae of T. irinae lack anterior branchial lobes and posterior lobes originate from a thin and long stalk and are free along their entire length, the ventral being much shorter than the dorsal (see Gagaev, 2009: Fig. a–b). Terebellides gentili Lavesque, Hutchings, Daffe, Nygren & Londoño-Mesa, 2019 also bears conspicuously long notochaetae (not explicitly mentioned in the description but see Lavesque et al., 2019: Fig. 10A). Nevertheless, this species clearly differs from T. longiseta sp. nov. in having fewer and thinner notochaetae and conspicuous papillar projections on the outer edge of the branchial lamellae, that are absent in T. longiseta sp. nov. Terebellides yangi resembles T. longiseta sp. nov. in having greatly developed anterior branchial lobes but differs in length and number of thoracic notochaetae (far more numerous and longer in the African species). On the other hand, several African non-type specimens identified as T. jorgeni may correspond to T. longiseta sp. nov. (see note below). One specimen from St. 133 showed a scar due to a parasitic copepod, similar to those reported for specimens of T. shetlandica by Parapar et al. (2016c). This was the only parasitized specimen observed across all material examined in this work.

Terebellides ramili sp. nov. Figures 11D, 28B, 33, 34, 37; Tables 1, 2 urn:lsid:zoobank.org:act: 97DCCE83-A2BC-48EF-B84A-BB20123827AF Material examined. Type material. Four specimens: holotype (MNCN16.01 /18615); three paratypes (MNCN 16.01 /18613, 16.01/18614 and 16.01/18616). Non-type material. One specimen (NHMD-231438, Table 1). Diagnosis. Body small/medium sized (18.5 mm in length); TC1–5 ventrally whitish. Branchial anterior lobe absent; posterior ventral lobes thinner than dorsal ones, with terminal filament and directly emerging from branchial stem. TC1 notopodia and notochaetae as long as following ones. Thoracic neurochaetae with rostrum/capitium length about 1/1, and capitium with a first row of 5−6 small teeth followed by similar sized ones. Description based on holotype Measurements and general body features. Complete specimen, 18.5 mm long and 1.5 mm wide; female with oocytes in body cavity (Fig. 28B, 33 A−B). Body tapering posteriorly with segments increasingly shorter and crowded towards pygidium. Prostomium compact; short tentacular membrane surrounding mouth, devoid of buccal tentacles. SGI as an expanded structure below tentacular membrane (Fig. 33A). Lateral lappets on SGIII–VII (TC1–5), larger in SGIII–IV (Fig. 33B). Branchiae. Branchiae arising as single structure from SGIII, with a single stalked mid-dorsal branch (Fig. 28B) having one pair of dorsal (upper), non-fused lobes and one pair of shorter ventral (lower) lobes, neither fused together nor to dorsal ones, with terminal filament (Fig. 28B, 33 A−B). Anterior projection of dorsal lobes (lobe 5) absent. Both sides of branchial lamellae with cilia; rows and/or tufts or papillae not seen. Thorax. Eighteen pairs of notopodia (SGIII–XX), with those of TC1 as long as subsequent ones. Neuropodia as sessile pinnules, from TC6 (SGVIII) to pygidium, with uncini in single rows starting from TC7 (SGIX) throughout. First neuropodia (TC6) with 4–5 sharply bent, acute-tipped, geniculate chaetae (Fig. 34A) showing minute teeth forming a capitium. From TC7, neuropodia with up to 6–10 uncini per torus in one row, with long shafted denticulate hooks, rostrum about same length as capitium, with 8–10 small teeth above main fang, surmounted by two rows of several teeth of same size (Fig. 34 B–D). Abdomen. Thirty-one neuropodia as erect pinnules, with about 25−30 uncini per torus having four teeth above main fang surmounted by an upper crest of 4–5 teeth and a variable number of smaller teeth (Fig. 34 E–F). Other body features. Pairs of nephridial papillae both at TC1; dorsal paired nephridial openings in anterior thoracic notopodia not seen. Pygidium blunt, as funnel-like depression. Five anterior thoracic chaetigers (TC1−5) ventro-laterally whitish (Fig. 33A); last two (TC4–5) more pigmented. Methyl green staining pattern. Anterior CH 1 to CH 3 solid; CH 4 to CH 12 striped; being CH 4 and CH 5 much more marked than previous ones, and CH 12 faded; J-shaped glandular region slightly marked lateral to CH 2 and CH 3; near pattern 5 of Schüller & Hutchings (2010) (Fig. 37). Variability. Body 6.0 mm long in the only complete (and probably immature) paratype (MNCN16.01/18613). Specimen NHMD-231438 (Fig. 33C), collected during the Galathea expedition and originally identified as T. stroemii by Kirkegaard (1959), has been identified here as T. af. ramili. It is a 22-mm long female with oocytes that was collected nearby the type location and at similar depths (Table 1). However, its identity cannot be fully confirmed as colouration of TC4–TC5 is different than others being more widely distributed in TC4 and much less in TC5 (Fig. 33C). Moreover, this specimen bears shorter branchial ventral lobes than in T. ramili sp. nov. and lacks terminal filament. Type locality. Off Congo; 190 m depth (Table 1). Distribution and bathymetry. Off Congo and Namibia; 190−537 m depth (Fig. 11D; Table 1). Etymology. The species is named after Dr. Francisco Ramil (Universidade de Vigo, Spain), for his numerous contributions to the taxonomy of marine invertebrates, especially Cnidarians, in many world seas but specifically in the Iberian Peninsula, Antarctica and the Atlantic African littoral. Remarks. The conspicuous white colouration of T. ramili sp. nov. resembles that of the boreal Terebellides gracilis Malm, 1874, recently reported from Iceland by Parapar et al. (2011) and the Adriatic Sea by Parapar et al. (2013). The type material redescribed by Parapar et al. (2011) shows a homogeneous colour pattern between TC1 and TC4, while in T. ramili sp. nov. it appears from TC1 to TC5 being even more conspicuous in TC4 and TC5. Furthermore, TC1 notopodia and notochaetae in the Mediterranean specimens of T. gracilis are smaller than in other chaetigers (similar throughout or slightly larger in T. ramili sp. nov.) and the thoracic uncini show large anterior teeth in the capitium (Parapar et al., 2011: Fig. 10C). These teeth are closer to Type 1, as it happens in T. longiseta sp. nov. and T. kirkegaardi sp. nov., or Type 2, as in T. fauveli sp. nov., and different to the Type 4 present in T. ramili sp. nov. Moreover, T. ramili sp. nov. also differs from the three aforementioned species in the branchial shape, size of TC1 and ventral colour pattern (see above).

Terebellides congolana sp. nov. Figures 11A, 12A, 13���15, 37; Tables 1, 2 urn:lsid:zoobank.org:act: F56164BC-1B78-4ECE-ACA5-543E5D75EB90 Material examined. Type material. Four specimens: holotype (MNCN 16.01 /18582); three paratypes (MNCN 16.01 /18581, 16.01/18583 and 16.01/18584, Table 1). Diagnosis. Body large (31���33 mm in length), with branchial anterior lobe, posterior ventral lobes much smaller than dorsal ones, with short terminal filament, and emerging after fusion line of dorsal ones. TC1 notopodia and notochaetae much longer than following ones. Thoracic neurochaetae with rostrum / capitium length about 1/1, and capitium with a first row of 4���5 big teeth followed by a second row of much smaller, progressively smaller teeth. Description based on holotype Measurements and general body features. Complete specimen, 31.0 mm long and 3.0 mm wide (Fig. 12A); female with oocytes in body cavity. Body tapering posteriorly, with segments increasingly shorter and crowded towards pygidium. Prostomium compact; large tentacular membrane surrounding mouth with typical buccal tentacles with expanded tips (Fig. 13A, E). SGI as an expanded structure below tentacular membrane (Fig. 13 A���B). Lateral lappets on SGIII���VIII (TC1���6), larger in SGIII���VII (TC1���5) (Fig. 13 A���E). Low oval-shaped glandular region in CH 3 in some specimens (Fig. 13B), but not evident. Branchiae. Branchiae arising as single structure from SGIII, with a single short-stalked mid-dorsal branch (Fig. 12A, 13 A���B, E), one pair of long dorsal (upper) lobes 50% fused, reaching TC6���7 (Fig. 13C) and one pair of ven- tral (lower) lobes about 1/5 as long as dorsal ones), not fused together and arising from mid-length of dorsal lobes fusion line (Fig. 13 A���B). Anterior projection of dorsal lobes (lobe 5) large, about 1/4 length of posterior dorsal lobes (Fig. 13E). Pointed projection of posterior region only in lower lobes, as a short and thick terminal filament (Fig. 13A). Both sides of branchial lamellae with several parallel bent rows of cilia and ciliated papillae on outer edge (Fig. 14 C���D). Thorax. Eighteen pairs of notopodia (SGIII���XX), with dorsal ciliated papillae (Fig. 14 E���F). TC1 much more developed and with longer notochaetae than subsequent ones (Fig. 13B, E). All notochaetae as simple capillaries. Neuropodia as sessile pinnules from TC6 (SGVIII) to body end, with uncini in single rows starting from TC7 (SGIX) throughout. First neuropodia (TC6) with four sharply bent, acute tipped, geniculate chaetae (Fig. 15B) having minute teeth forming an ill-defined capitium. From TC7, neuropodia with 8���14 uncini per torus in one row, with long-shafted denticulate hooks, rostrum about same length as capitium, with 4���5 big teeth above main fang surmounted by several much smaller denticles (Fig. 15 C���E). Abdomen. About 40% of body length, with 31 pairs of neuropodia as erect pinnules (Fig. 15G); about 25���30 uncini per torus having four teeth above main fang surmounted by 3���4 teeth in irregular middle row and an upper crest of several smaller teeth (Fig. 15H). Other body features. One well-developed nephridial papilla behind each TC1 notopodium (Fig. 14E), and two pairs of nephridial openings in TC4 and TC5 (Fig. 14F). Pygidium blunt, funnel-like depression. Methyl green staining pattern. Anterior CH 1 to CH 9 solid; CH 10 to CH 18 striped; being CH 10 to CH 11 much more marked than following; J-shaped glandular region marked lateral to CH 3; near pattern 5 of Sch��ller & Hutchings (2010) (Fig. 37). Variability. Body between 31 and 33 mm in length. Type locality. Off Congo (Table 1). Distribution and bathymetry. Off Congo; sandy mud; 47���167 m depth (Fig. 11A; Table 1). Etymology. The name of the species refers to the type location, the Republic of Congo. Remarks. Terebellides anguicomus M��ller, 1858 sensu Sol��s-Weiss et al. (1991) resembles T. congolana sp. nov. in having large sized-branchiae reaching TC6 but differs in having a large transverse dorsal hump on TC5 and 17 thoracic chaetigers (18 in T. congolana sp. nov. and most species of the genus, see key below). Terebellides congolana sp. nov. also differs from other African species in having posterior ventral branchial lobes that are much smaller and located distally, but the following ones also have this character: T. rigel Sch��ller & Hutchings, 2013; T. mediterranea Parapar, Mikac & Fiege, 2013; T. akares Hutchings, Nogueira & Carrerette, 2015, T. persiae and T. hutchingsae. However, T. rigel is a deep-water species (> 2000 m) from the Weddell Sea and does not bear long TC1 notopodia and notochaetae; T. akares was described from coral reefs (Lizard Island, NE Australia) and has a distinctly short abdomen; T. persiae is a shallow-water species from the Iranian coast, that has a much more developed anterior branchial lobe and a distinct dorsal hump at TC6; T. hutchingsae is also a shallow subtidal species from the Gulf of Thailand, that bears geniculate chaetae in two chaetigers, TC5 and TC6, instead of only one in TC6. The closest species to T. congolana sp. nov. is T. mediterranea, a shallow-water species (31 m depth) from the Adriatic Sea; it also bears branchiae with a similar shape and very small ventral posterior lobes arising near the distal end of the branchiae, and TC1 notopodia and notochaetae longer than following, but it differs from the new species in having a shorter body (21 mm in length vs. 31 mm in T. congolana sp. nov.) and a much larger tentacular membrane. Terebellides europaea Lavesque, Hutchings, Daffe, Nygren & Londo��o-Mesa, 2019, from the French coast of the Bay of Biscay, also shares with T. congolana sp. nov. the long notopodia and notochaetae of TC1, but it differs from the new species in having papillar projections over the edge on anterior branchial lamellae, much bigger ventral branchial lobes and attached to the branchial stem, and in lacking ciliated papillae in branchial lamellae., Published as part of Parapar, Julio, Martin, Daniel & Moreira, Juan, 2020, On the diversity of Terebellides (Annelida, Trichobranchidae) in West Africa, seven new species and the redescription of T. africana Augener, 1918 stat. prom., pp. 1-61 in Zootaxa 4771 (1) on pages 18-23, DOI: 10.11646/zootaxa.4771.1.1, http://zenodo.org/record/3798452, {"references":["Schuller, M. & Hutchings, P. A. (2010) New insights in the taxonomy of Trichobranchidae (Polychaeta) with the description of a new Terebellides from Australia. Zootaxa, 2395 (1), 1 - 16. https: // doi. org / 10.11646 / zootaxa. 2395.1.1","Muller, F. (1858) Einiges uber die Annelidenfauna der Inseln Santa Catharina an der brasilianischen Kuste. Archiv fur Naturgeschichte, Berlin, 24, 211 - 220.","Solis-Weiss, V., Fauchald, K. & Blankestein, A. (1991) Trichobranchidae (Polychaeta) from shallow warm water areas in the Western Atlantic Ocean. Proceedings of the Biological Society of Washington, 104 (1), 147 - 158.","Schuller, M. & Hutchings, P. A. (2013) New species of Terebellides (Polychaeta: Trichobranchidae) from deep Southern Ocean. Zootaxa, 3619 (1), 1 - 45. https: // doi. org / 10.11646 / zootaxa. 3619.1.1","Parapar, J., Mikac, B. & Fiege, D. (2013) Diversity of the genus Terebellides (Polychaeta: Trichobranchidae) in the Adriatic Sea with the description of a new species. Zootaxa, 3691 (3), 333 - 350. https: // doi. org / 10.11646 / zootaxa. 3691.3.3","Hutchings, P. A., Matos Nogueira, J. M. de & Carrerette, O. (2015) Telothelepodidae, Thelepodidae and Trichobranchidae (Annelida, Terebelliformia) from Lizard Island, Great Barrier Reef, Australia. Zootaxa, 4019 (1), 240 - 274. https: // doi. org / 10.11646 / zootaxa. 4019.1.12","Lavesque, N., Hutchings, P., Daffe, G., Nygren, A. & Londono-Mesa, M. H. (2019) A revision of the French Trichobranchidae (Polychaeta), with descriptions of nine new species. Zootaxa, 4664 (2), 151 - 190. https: // doi. org / 10.11646 / zootaxa. 4664.2.1"]}

Terebellides fauveli sp. nov. Figures 11B, 12B, 16���20, 37; Tables 1, 2 urn:lsid:zoobank.org:act: F388A555-F6F0-48A8-93C5-C244DADDA76B Material examined. Type material. Thirty-six specimens: holotype (NHMD-636920); thirty-five paratypes (NHMD-231435, NHMD-231442���231445, NHMD-231447, NHMD-231450���231452, NHMD-231461, NHMD- 231463, NHMD-636921 to NHMD-636922). Non-type material. Seven specimens (MNCN 16.01 /18585 to 16.01/18590, Table 1). Diagnosis. Body of medium/large size (15���35 mm in length). Branchiae comma-shaped, with anterior lobe and posterior ventral lobes thinner than dorsal ones, directly emerging from branchial stem and with well-developed thin terminal filament. TC1 notopodia and notochaetae longer than following thoracic ones. Thoracic neurochaetae with rostrum / capitium length about 4/1, and capitium with a first row of 2���3 very large teeth followed by three rows of also large, but smaller teeth. Description based on holotype Measurements and general body features. Complete specimen, 30.0 mm long and 3.0 mm wide (Fig. 12B). Body tapering posteriorly with segments increasingly shorter and crowded towards pygidium. Prostomium compact; large tentacular membrane surrounding mouth, with some typical buccal tentacles with expanded tips. SGI as expanded structure, below tentacular membrane (Fig. 16 B���C). Low lateral lappets on SGIII���VII (TC1���5) much larger in SGIII���V (TC1���3) and latero-dorsally white in TC3���4 (Fig. 16 A���B). Branchiae. Branchiae comma-shaped, arising as single structure from SGIII, consisting of a single short stalked mid-dorsal branch with one pair of long dorsal (upper) unfused lobes, reaching TC6���7 (Fig. 12B, 16 B���C), and one pair of ventral (lower) smaller and thinner lobes (about half length of dorsal), not fused together and emerging after a short fusion line of dorsal lobes (Fig. 19 A���B). Anterior projection of dorsal lobes (lobe 5) about 1/7 length of posterior dorsal lobes (Fig. 16A, C). Pointed projection of posterior region only in lower lobes, as a thin but welldeveloped terminal filament (Fig. 16D, 17 B���C, 19A���B). Both sides of branchial lamellae with rows of cilia (Fig. 17 B���C, 19C); ciliated tufts or papillae not seen. Thorax. Eighteen pairs of notopodia (SGIII���XX), much more developed and with longer notochaetae in TC1 than in following ones (Fig. 16 C���D, 17A���B, 19D). All notochaetae as simple capillaries. Neuropodia as sessile pin- nules, from TC6 (SGVIII) to pygidium, with around 15 uncini in single rows starting from TC7 (SGIX) throughout. First neuropodia (TC6) with four sharply bent, acute tipped, geniculate chaetae (Fig. 18A) having small minute teeth forming an ill-defined capitium (Fig. 19 E���F). From TC7, neuropodia with 8���14 uncini per torus in one row, with long shafted denticulate hooks, a very long rostrum about four times longer than capitium, with 2(3) very big teeth above main fang, surmounted by two rows of 3���4 also big, but smaller teeth and an upper crest of several smaller denticles (Fig. 18 B���C). Abdomen. About 40% of body length, with 29 pairs of neuropodia as erect pinnules, with around 30 uncini per torus having three teeth above main fang surmounted by an upper crest of several minute teeth (Fig. 18D). Other body features. One nephridial papilla behind each TC1 notopodium and nephridial openings in TC4 and TC5 notopodia. Pygidium blunt, funnel-like depression. Methyl green staining pattern. Anterior CH 1 to CH 9 solid; CH 10 to CH 18 striped; being CH 10 to CH 11 much more marked than following; J-shaped glandular region marked lateral to CH 3; near pattern 5 of Sch��ller & Hutchings (2010) (Fig. 37). Variability. Body between 15 and 35 mm in length. Type locality. Ivory Coast; 80���90 m depth (Table 1). Distribution and bathymetry. Widely distributed along the West African coasts, from Liberia to South Angola; 42���200 m depth (Fig. 11B; Table 1). Etymology. The species is named after the French zoologist Pierre Fauvel (1866���1958) for his many contributions to the study of the Polychaeta across world oceans, especially in Europe and Africa. Remarks. Three Terebellides species have been previously described with TC1 provided with large notopodia and long notochaetae: T. kobei Hessle, 1917 (Japan), T. californica Williams, 1984 (California), T. mediterranea, and two in this work: T. congolana sp. nov. and T. fauveli sp. nov. Terebellides fauveli sp. nov. has shorter TC1 notopodia and notochaetae than T. kobei, lacks a conspicuous triangular dorsal projection in TC3 notopodia (present in T. kobei), has a white lateral colouration in anterior chaetigers (absent in T. kobei) and has a different capitium denticulation, being all teeth small and of similar size in T. kobei, as illustrated by Hessle (1917: textfig. 32, p. 140). Terebellides californica was described from shelf and slope depths in the Pacific Ocean (Oregon to Western Mexico) and is characterized by the author only by the ��� very well developed first chaetiger with greatly prolonged fine notosetae ��� (Williams, 1984: p. 128), which is clearly longer than the one in T. fauveli sp. nov. and lacks any special development in TC3 and body colour pattern. This species was later redescribed by Hilbig (2000) as having a ��� trilobed structure of the peristomium ��� as potential new diagnostic character, which is not present in T. fauveli sp. nov. However, in our opinion, the relevance of this character should be considered with caution as its presence in T. californica has not been sufficiently assessed. Terebellides mediterranea most closely resembles T. fauveli sp. nov. in branchial shape. However, T. fauveli sp. nov. bears larger branchiae that reach TC6 (instead of TC3���4) and has posterior branchial lobes with terminal filament. Moreover, both species differ in number and size of the denticulation of thoracic uncini, with 3���4 mediumsized teeth above main fang and surmounted by a row of 6���7 slightly shorter tooth in T. mediterranea (see Parapar et al., 2013: Fig. 7B). Terebellides anguicomus and T. lanai Sol��s-Weiss et al., 1991 resemble T. fauveli sp. nov. in the shape (commalike) and size of the branchiae, also reaching TC6. However, T. lanai bears branchial lobes fused for most of their length, and T. anguicomus has a large transverse dorsal hump on TC5, 17 thoracic chaetigers (instead of 18) and a shorter TC1. While some of the French species recently described by Lavesque et al. (2019), such as T. lilasae Lavesque, Hutchings, Daffe, Nygren & Londo��o-Mesa, 2019, have similar general branchial shape as in T. fauveli sp. nov., the capitium denticulation of the thoracic uncini is very different; in fact, the shape of the thoracic uncini in T. fauveli sp. nov. has not been recorded so far in any other species of the genus. Among the West African species, T. fauveli sp. nov. apparently presents the widest bathymetric and geographic distribution. Non-type specimens collected off Congo (N���Kossa gas field, Table 1) show subtle differences in the shape and size of the terminal filament of lower branchial lobes, size of TC1 and thoracic uncini teeth (cfr. Fig. 17���18 vs. 19���20). Therefore, we cannot discard they may represent a different, close taxon. More extensive sam- pling across West Africa and further morphological and molecular analyses may help to test the present wide distribution of T. fauveli sp. nov. and the possible existence of several cryptic species., Published as part of Parapar, Julio, Martin, Daniel & Moreira, Juan, 2020, On the diversity of Terebellides (Annelida, Trichobranchidae) in West Africa, seven new species and the redescription of T. africana Augener, 1918 stat. prom., pp. 1-61 in Zootaxa 4771 (1) on pages 23-28, DOI: 10.11646/zootaxa.4771.1.1, http://zenodo.org/record/3798452, {"references":["Schuller, M. & Hutchings, P. A. (2010) New insights in the taxonomy of Trichobranchidae (Polychaeta) with the description of a new Terebellides from Australia. Zootaxa, 2395 (1), 1 - 16. https: // doi. org / 10.11646 / zootaxa. 2395.1.1","Hessle, C. (1917) Zur Kenntnis der terebellomorphen Polychaeten. Zoologiska Bidrag fran Uppsala, 5, 39 - 258.","Williams, S. J. (1984) The status of Terebellides stroemi (Polychaeta; Trichobranchidae) as a cosmopolitan species, based on a worldwide morphological survey, including description of new species. In: Hutchings, P. A. (Ed.), Proceedings of the First International Polychaete Conference, Sydney, Australia, 1984. The Linnean Society of New South Wales, Sydney, pp. 118 - 142.","Hilbig, B. (2000) Family Trichobranchidae Malmgren, 1866. In: Blake, B., Hilbig, B. & Scott, P. A. (Eds.), Taxonomic Atlas of the Benthic Fauna of the Santa Maria Basin and the Western Santa Barbara Channel. Vol. 7. The Annelida Part 4. Polychaeta: Flabelligeridae to Sternaspidae. U. S. Dept. of the Interior, Minerals Management Service, Pacific OCS Region, Camarillo, California, pp. 295 - 309.","Parapar, J., Mikac, B. & Fiege, D. (2013) Diversity of the genus Terebellides (Polychaeta: Trichobranchidae) in the Adriatic Sea with the description of a new species. Zootaxa, 3691 (3), 333 - 350. https: // doi. org / 10.11646 / zootaxa. 3691.3.3","Solis-Weiss, V., Fauchald, K. & Blankestein, A. (1991) Trichobranchidae (Polychaeta) from shallow warm water areas in the Western Atlantic Ocean. Proceedings of the Biological Society of Washington, 104 (1), 147 - 158.","Lavesque, N., Hutchings, P., Daffe, G., Nygren, A. & Londono-Mesa, M. H. (2019) A revision of the French Trichobranchidae (Polychaeta), with descriptions of nine new species. Zootaxa, 4664 (2), 151 - 190. https: // doi. org / 10.11646 / zootaxa. 4664.2.1"]}

Terebellides kirkegaardi sp. nov. Figures 11B, 21A, 22–24, 37; Tables 1, 2 urn:lsid:zoobank.org:act: 82974B42- 2924-48 A8-BD1A-254FED0F881B Material examined. Type material. Holotype (NHMD-231439); paratypes: 37 specimens (NHMD-636923 to NHMD-636925), all from the same original vial as the holotype (Table 1). Diagnosis. Body of medium/large size (15–30 mm in length). Branchiae with a long and thick stalk; anterior lobe large; posterior ventral lobes about as long as dorsal ones, with short terminal filaments, emerging directly from branchial stem. TC1 notopodia and notochaetae shorter than following thoracic ones. Thoracic neurochaetae with rostrum / capitium length about 2/1, and capitium with a first row of 2–5 medium-sized teeth followed by progressively smaller ones. Description based on holotype Measurements and general body features. Complete specimen, 28.0 mm long and 2.5 mm wide (Fig. 21A, 22 A−B); body tapering posteriorly with segments increasingly shorter and crowded towards pygidium. Prostomium compact; large tentacular membrane surrounding mouth, with typical buccal tentacles with expanded tips (Fig. 22 A−Β). SG1 as an expanded structure below tentacular membrane (Fig. 22A, 24A). Lateral lappets and ovalshaped glandular region in TC3 not present. Branchiae. Branchiae arising as single structure from SG3, consisting of a single very long (about same length as dorsal posterior lobes) stalked mid-dorsal branch (Fig. 21A, 22 A−D, 24A), with one pair of dorsal (upper) un- fused lobes reaching TC4 or TC6 (if branchial stalk bent backwards); a pair of ventral (lower) lobes about as long as dorsal ones but thinner, not fused together and arising directly from stalk (Fig. 21A, 22 A−D, 23A, 24A). Ante- rior projection of dorsal lobes (lobe 5) very well developed, about half length of posterior dorsal lobes (Fig. 21A, 22 A−D, 23A, 24A). Pointed projection of posterior region of both upper and lower lobes much longer in ventral ones, becoming a terminal filament (Fig. 23A). Both sides of branchial lamellae ciliated, arrangement in rows and/ or tufts or papillae not seen. Thorax. Eighteen pairs of notopodia (SG3−20); that of TC1 shorter than subsequent ones (Fig. 24 A−B), with notochaetae as simple capillaries, shorter in number and length than following ones. Neuropodia as sessile pinnules, from TC6 (SG8) to pygidium, with uncini in single rows starting from TC7 (SG9) throughout. First neuropodia (TC6) with 4–5 sharply bent, acute-tipped, geniculate chaetae (Fig. 23B, 24 C−D) having minute teeth forming a very low marked capitium (Fig. 24D). From TC7, neuropodia with 11–17 uncini per torus in one row (Fig. 24E) with long shafted denticulate hooks, rostrum about two times longer than capitium, with 2−5 big teeth above main fang, and surmounted by a crest of smaller denticles (Fig. 24 F−G). Abdomen. About 40% of body length, with 31 pairs of neuropodia as erect pinnules with about 20–25 uncini per torus having four teeth above main fang surmounted by a crest of several teeth of same and/or smaller length (Fig. 23D). Other features. Papilla on first thoracic notopodia not seen; button-hole-like pairs of dorsal nephridial openings on, at least, each SG7 (TC5) notopodium (Fig. 23 B−C); second pair not seen. Pygidium blunt, as funnel-like depression. Methyl green staining pattern. Anterior CH 1 to CH 3 solid; CH 4 to CH 9 striped; fading from CH 10 to CH 12; J-shaped glandular region marked lateral to CH 3; pattern 5 of Schüller & Hutchings (2010) (Fig. 37). Variations. Terebellides kirkegaardi sp. nov. is a medium-sized species (15−30 mm long). Eggs were visible in body cavity of females across all length range. Most specimens are in good conditions, with bodies and branchiae complete. Type locality. Cameroon; 8–9 m depth (Table 1). Distribution and bathymetry. Victoria (aka Limbé, Cameroon); 8−9 m depth (Fig. 11B; Table 1). Etymology. This species is named in honour of Danish researcher Jørgen Bagger Kirkegaard (1920−2006), who participated in the Galathea and Atlantide Deep Sea Expeditions. His 1958 publication on West African sedentary polychaetes included most of the specimens studied in the present work. Remarks. Terebellides kirkegaardi sp. nov. is mostly characterised by its long branchial stalk and well-developed anterior triangular lobe, coupled with a TC1 notopodia shorter than following, and very low marked capitium teeth in TC6 thoracic uncini (only detected with SEM). The branchial appearance is similar across most specimens studied (cfr. Fig. 21A, 22 A–D, 24A)—but see Fig. 22 E–F, 23A—giving rise to a characteristic body profile that differs from any other known species of the genus. Terebellides kirkegaardi sp. nov. most closely resembles Terebellides canopus Schüller & Hutchings, 2013, Terebellides mira Schüller & Hutchings, 2013 (both from deep waters off South Western Atlantic Ocean), and Terebellides sepultura Garraffoni & Lana, 2003 (from Brazilian coasts). However, they lack the anterior projection of branchial lobes and posterior lobes are free from each other. Terebellides mira also bears a branchial stem that is much longer than the proper branchial lobes. Two specimens from Myanmar, identified as Terebellides cf. woolawa Hutchings & Peart, 2000 by Parapar et al. (2016a), also show long branchial stems, but differ from T. kirkegaardi sp. nov. in having an even more developed, non-triangular anterior lobe, as well as smaller postero-ventral lobes. Furthermore, T. woolawa as described by Hutchings & Peart (2000) bears a similar anterior lobe, but the branchial stem is much shorter.

Terebellides augeneri sp. nov. Figures 2B, 8���10, 11A, 37; Tables 1, 2 urn:lsid:zoobank.org:act: 147575A6-3605-4327-A3AD-F5F1C80A3D0D Material examined. Type material. Six specimens: holotype (MNCN 16.01 /18579); five paratypes (MNCN 16.01 /18577, 16.01/18580, 16.01/1858 and NHMD-636919, Table 1). Diagnosis. Small/medium-sized species (7���19 mm in length). Branchial anterior lobe absent; posterior ventral lobes thinner than dorsal ones, with terminal projections, directly emerging from branchial stem. TC1 notopodia and notochaetae as long as following. Thoracic neurochaetae with rostrum / capitium length about 1/1, and capitium with a first row of 5���6 medium sized teeth followed by progressively smaller teeth. Description based on holotype Measurements and general body features. Complete specimen, 19 mm long and 1.5 mm wide; female with oocytes in body cavity (Fig. 2B). Body tapering posteriorly with segments increasingly shorter and crowded towards pygidium. Prostomium compact; large tentacular membrane surrounding mouth, with typical buccal tentacles and expanded tips (Fig. 8C, 9A). SGI as an expanded structure below tentacular membrane. Lateral lappets on SGIII��� VII (TC1���5), larger in SGIV���VI (TC2���4) (Fig. 2B, 8 C���D, 9A). Branchiae. Branchiae arising as single structure from SGIII, with a single stalked mid-dorsal branch, one pair of dorsal (upper) not-fused lobes, and a pair of shorter ventral (lower) lobes, neither fused to each other, nor to dorsal ones, with short terminal projections (Fig. 9C). Anterior projection of dorsal lobes (lobe 5) absent (Fig. 2B). Both sides of branchial lamellae having several parallel rows of cilia and low ciliated tufts on lamellar outer edge (Fig. 9 B���C). Thorax. Eighteen pairs of notopodia (SGIII���XX), those of TC1 about as long as following ones. All notochae- tae as simple capillaries. Neuropodia as sessile pinnules from TC6 (SGVIII) to body end, with uncini in single rows, from TC7 (SGIX) throughout. First neuropodia on TC6, with 4���5 sharply bent, acute tipped, geniculate chaetae with minute teeth forming a well-defined capitium (Fig. 10 C���D). From TC7, neuropodia with up to 5���10 uncini per torus in one row, with long shafted denticulate hooks, rostrum about same length as capitium, with 5���6 medium-sized teeth above main fang, and surmounted by two rows of progressively shorter teeth (Fig. 10 A���B). Abdomen. Thirty-one pairs of neuropodia, as erect pinnules with about 20���25 uncini per torus, with four teeth above main fang surmounted by an upper crest of similar sized teeth (Fig. 10 E���F) and several smaller teeth above. Other body features. Nephridial (?) papilla behind TC1; nephridial openings dorsal to any anterior thoracic notopodium not seen. Pygidium blunt, as a funnel-like depression. Methyl green staining pattern. Anterior CH 1 to CH 4 solid; CH 5 to CH 11 striped; near pattern 1 of Sch��ller & Hutchings (2010) (Fig. 37). Variability. Body ranging from 7.0 to 19.0 mm in length. Type locality. Off Angola; 73 m depth (Table 1). Distribution and bathymetry. Off Angola; 72���83 m depth (Fig. 11A; Table 1). Etymology. This species is named after the German scientist and prolific marine zoologist Hermann Augener (1872���1938), as an homage to his numerous contributions to polychaete taxonomy. Remarks. The branchiae of T. augeneri sp. nov. resemble those of T. hutchingsae Parapar, Moreira & Martin, 2016 in bearing ventral lobes much less developed than the dorsal ones and arising from the base of the latter, but differ in having wider and longer lobes and in lacking a longer terminal projection. Both species also differ in the size of the ciliature in branchial lamellae outer edge (much lower in T. augeneri sp. nov.), in the shape of thoracic uncini (with teeth surmounting the rostrum much bigger in T. augeneri sp. nov.) and in bearing geniculate chaetae in CH 5 and CH 6 (only in CH 6 in T. augeneri sp. nov.). Terebellides ceneresi Lavesque, Hutchings, Daffe, Nygren & Londo��o-Mesa, 2019 has in common with T. augeneri sp. nov. the general branchial shape, with very similar branchial lobes and ciliary tufts on both sides of the outer edge of lamellae and no papillar projections pointing over their edge. Nevertheless, both species differ in the thoracic uncini, both in the shape of main fang (straight in T. augeneri sp. nov.; terminally bent in T. ceneresi) and the denticulation of capitium (5���6 teeth in first row in T. augeneri sp. nov.; 3���4 in T. ceneresi). Terebellides shetlandica Parapar, Moreira & O���Reilly, 2016 also bears ventral branchial lobes not fused to dorsal ones and arising directly from the branchial stem. However, it is much smaller than T. augeneri sp. nov. (up to 15 mm; Parapar et al., 2016c), the four posterior lobes are of similar size, and the branchial lamellae do not bear ciliated papillae. In African Atlantic waters T. augeneri sp. nov. most closely resembles T. ramili sp. nov. (see below). However, it inhabits much deeper bottoms and is unique among African species because in the thoracic uncini all teeth surmounting the rostrum are very small and of the same size; in all other species, the first-row teeth are always larger than those of posterior rows., Published as part of Parapar, Julio, Martin, Daniel & Moreira, Juan, 2020, On the diversity of Terebellides (Annelida, Trichobranchidae) in West Africa, seven new species and the redescription of T. africana Augener, 1918 stat. prom., pp. 1-61 in Zootaxa 4771 (1) on pages 13-18, DOI: 10.11646/zootaxa.4771.1.1, http://zenodo.org/record/3798452, {"references":["Schuller, M. & Hutchings, P. A. (2010) New insights in the taxonomy of Trichobranchidae (Polychaeta) with the description of a new Terebellides from Australia. Zootaxa, 2395 (1), 1 - 16. https: // doi. org / 10.11646 / zootaxa. 2395.1.1","Parapar, J., Moreira, J. & Martin, D. (2016 a) On the diversity of the SE Indo-Pacific species of Terebellides (Annelida; Trichobranchidae), with the description of a new species. PeerJ, 4, e 2313. https: // doi. org / 10.7717 / peerj. 2313","Lavesque, N., Hutchings, P., Daffe, G., Nygren, A. & Londono-Mesa, M. H. (2019) A revision of the French Trichobranchidae (Polychaeta), with descriptions of nine new species. Zootaxa, 4664 (2), 151 - 190. https: // doi. org / 10.11646 / zootaxa. 4664.2.1","Parapar, J., Moreira, J. & O'Reilly, M. (2016 c) A new species of Terebellides (Polychaeta: Trichobranchidae) from Scottish waters with an insight into branchial morphology. Marine Biodiversity, 46, 211 - 225. https: // doi. org / 10.1007 / s 12526 - 015 - 0353 - 5"]}

Terebellides nkossa sp. nov. Figures 11C, 28A, 29–32, 37; Tables 1, 2 urn:lsid:zoobank.org:act: 8C262B7A-F8EC-4ABC-A6AE-538652C71D1B Material examined. Type material. Fifty specimens: holotype (MNCN16.01 /18594); forty-nine paratypes (MNCN16.01 /18592, 16.01/18593 and 16.01/18595 to 16.01/18610). Non-type material. Five dried-out specimens (MNCN16.01 /18611 and MNCN16.01 /18612); one specimen (NHMD-231434) (Table 1). Diagnosis. Body small sized (5–15 mm in length); semi-transparent body wall. Branchial anterior lobe absent; posterior lobes not fused; ventral ones thinner and shorter than dorsal ones, with long terminal filament, directly emerging from branchial stem. TC1 notopodia and notochaetae smaller than following ones. Thoracic neurochaetae with rostrum / capitium length about 1/1 and capitium with a first row of 4–7 medium-sized teeth followed by progressively shorter ones. Description based on holotype Measurements and general body features. Complete specimen, with coelomic cavity filled with oocytes, 12 mm long and 1.0 mm wide (Fig. 28A, 29A); body tapering posteriorly with segments increasingly shorter and crowded towards pygidium. Prostomium compact; tentacular membrane surrounding mouth, with a low number of buccal tentacles (Fig. 29A). SGI as an expanded structure below tentacular membrane (lower lip) (Fig. 29A, 30A). Lateral lappets weakly developed on SGIII–VII (CH 1–5). Branchiae. Branchiae arising as single structure from SGIII, with a single stalked mid-dorsal branch having of one pair of dorsal (upper) lobes not fused along their lengths, and a pair of ventral (lower) lobes much shorter, neither fused together nor to dorsal ones (Fig. 28A, 29A, 30 A−B, 32A). Anterior projection of dorsal lobes (lobe 5) not present. Pointed projection of posterior region of both upper and lower lobes much longer in ventral ones, becoming a long terminal filament (Fig. 30 A−B, 32A). Both sides of branchial lamellae with several parallel bent rows of cilia and several ciliated tufts near outer edge (Fig. 30 C−D). Thorax. Eighteen pairs of notopodia (SGIII−XX); those in TC1 slightly smaller than subsequent ones (Fig. 30A, E−F, 32A). Neuropodia as sessile pinnules, from TC6 (SGVIII) to pygidium, with uncini in single rows start- ing from TC7 (SGIX) throughout. First neuropodia (TC6) with 3–4 sharply bent, acute-tipped, geniculate chaetae with well-developed minute teeth forming a capitium (Fig. 31A). From TC7, neuropodia with up to 7–9 uncini per torus in one row (Fig. 31B), with long-shafted denticulate hooks, rostrum about same length as capitium, with 4−7 medium-sized teeth above main fang, surmounted by 4−6 slightly shorter teeth (Fig. 31C, 32 C−D). Abdomen. 29−30 pairs of neuropodia, as erect pinnules with about 20 uncini per torus (Fig. 31 D−E) having three teeth above main fang surmounted by two teeth above one in middle, an upper crest of two teeth and a variable number of smaller teeth (Fig. 31F). Other features. Paired, mulberry-like nephridial papilla behind first thoracic notopodia and dorsal to each SGVI and VII (CH 4 and CH 5) notopodium (Fig. 30A, E−F, 32A−B). Pygidium blunt, as funnel-like depression. Methyl green staining pattern. Anterior CH 1 to CH 4 solid; CH 5 to CH 11 striped; CH 12 and CH 13 only neuropodia slightly stained; pattern 1 of Schüller & Hutchings (2010) (Fig. 37). Variability. Most specimens of T. nkossa sp. nov. are complete, with well-defined branchiae, ranging from 5 to 15 mm long, showing intra-coelomic oocytes from 9-mm long specimens (Fig. 29D). The digestive tract main parts, especially the hind stomach, can be easily seen by transparency through the delicate body wall (Fig. 29C). The only specimen from the Atlantide cruise (NHMD-231434), identified as T. stroemii by Kirkegaard (1959), comes from shallow waters (108 m depth) off Sierra Leone, measures 7 mm in length and overall agrees with T. nkossa sp. nov. description, except in having much shorter, comma-shaped branchiae, both features not present in our specimens of this species, and therefore it was labelled as T. af. nkossa. Type locality. Gabon; 43 m depth (Table 1). Distribution and bathymetry. Gabon and Democratic Republic of Congo; 43−250 m depth (Fig. 11C; Table 1). Etymology. The species is named after the N’Kossa gas field located off Congo, where most specimens were collected. Remarks. The diagnostic characters above mentioned clearly distinguishes T. nkossa sp. nov. from all other species here described. However, it shares some branchial features with six previously described species: Terebellides mundora Hutchings & Peart, 2000 (Australia), Terebellides atlantis Williams, 1984 (New England slope), Terebellides parapari Lavesque, Hutchings, Daffe, Nygren & Londoño-Mesa, 2019, T. sepultura, T. irinae and T. shetlandica. Terebellides mundora differs from T. nkossa sp. nov. in having branchiae with posterior ventral lobes almost as long as dorsal ones and thoracic uncini with rostrum shorter than capitium, while the new species has ventral lobes much shorter and rostrum longer than capitium; T. sepultura has a very large branchial stalk (short in T. nkossa sp. nov.), and T. irinae has very long thoracic notopodial chaetae (short in T. nkossa sp. nov.). The Atlantic species T. atlantis, T. shetlandica and T. parapari closely resemble T. nkossa sp. nov. in their small body size (T. atlantis: 8–18 mm; T. shetlandica: 06– 19 mm; T. parapari: 8–23 mm and T. nkossa sp. nov.: 5–15 mm) and several other morphological features. Thus, even though the brief original description of T. atlantis (Williams, 1984) does not allow accurate comparisons, the Icelandic specimens described by Parapar et al. (2011) differ from T. nkossa sp. nov. in the size and shape of dorsal branchial lobes vs. ventral ones (which are all highly deciduous in the former) and the shape of thoracic uncini, which show the capitium endowed with minute and numerous teeth (type 4 in Parapar et al., 2016c) (long and scarce in T. nkossa sp. nov., type 3 in Parapar et al., 2016c). Terebellides shetlandica and T. parapari most closely resemble T. nkossa sp. nov. in general branchial shape with ventral branchial lobes only fused at base with dorsal ones and provided with a terminal filament and thoracic uncini. Furthermore, all three species were found at a similar depth range: 100–160 m for T. shetlandica, 120 m for T. parapari and 43–250 m for T. nkossa sp. nov. Nevertheless, T. nkossa sp. nov. mostly differs from T. shetlandica in the number of uncini per abdominal neuropodium (6–7 vs. ca. 20, respectively), and from T. parapari in having smaller TC1 notopodial and notochaetae than following (much longer in T. parapari) and having ciliated papillae dorsal to thoracic notopodia and ciliature in branchial lobes (absent in T. parapari). Other species with four-lobed branchiae are: Terebellides ehlersi McIntosh, 1885 (Fiji Islands), Terebellides intoshi Caullery, 1944 (Indonesia) and Terebellides lobatus Hartman & Fauchald, 1971 (New England). Nevertheless, all of them are much larger than T. nkossa sp. nov. (30−40 mm vs. 5−15 mm) and T. intoshi also bears two chaetigers with geniculate chaetae (cfr. Imajima & Williams, 1985), instead of one.

The number of described species of the genus Terebellides Sars, 1835 (Annelida, Trichobranchidae) has greatly increased in the last years, particularly in the North East Atlantic. In this context, this paper deals with several putative species recently delineated by molecular means within a well delimited clade of Terebellides. Species are characterised here by a combination of morphological characters, and a complementary nucleotide diagnostic approach. Three species were identified as the nominal species T. stroemii Sars, 1835, T. bigeniculatus Parapar, Moreira & Helgason, 2011 and T. europaeaLavesque et al., 2019. Five species are described as new: T. bakkenisp. nov., T. kongsrudisp. nov., T. norvegicasp. nov., T. ronningaesp. nov. and T. scoticasp. nov. The distinctive morphological characters refer to the branchial shape, absence or presence of papillae on lamellae of anterior margin of branchial dorsal lobes, absence or presence of ciliated papillae dorsal to thoracic notopodia, geniculate chaetae in one or two chaetigers, and the morphology of thoracic and abdominal uncini teeth. Furthermore, the description of T. bigeniculatus is revised and complemented after examination of type specimens. An updated identification key to all species of the genus in NE Atlantic and a proposal of a classification of different types of abdominal uncini to be used in taxonomy are also included.

Introduction: The first open-sea (non-coastal) Marine Protected Area in Argentina, named “Namuncurá I” (NMPA), was created in 2013 at Burdwood Bank (BB), an undersea plateau located about 200 km south from Malvinas Islands (Falkland Islands) and 150 km east from Staten Island, SW Atlantic Ocean. It comprises three different management areas: the central one (“core”, strict protection, only control and monitoring activities), surrounded by a “buffer” area (authorized activities, e.g. scientific research) and an external “transition” area (productive and extractive activities contemplated in the Management Plan). Beyond the transition area, only the southern shelf-break is protected, after the creation of the “Namuncurá II” MPA in December 2018. Objective: provide the inventory of polychaetes collected during 2016 and 2017 at the core (98 m depth), buffer (128 m depth), transition (133 m-189 m depth) areas of the Namuncurá I MPA, together with slope areas (220 m-798 m depth). Methods: taken with a trawl net used to characterize the faunal assemblages and to compare results with other Magellan areas. Multidimensional Scaling (MDS) and Cluster Analysis (CA) were applied to a Bray-Curtis similarity index to assess polychaete assemblages in the NMPA - BB slope and Magellan region respectively; SIMPER (Similarity Percentage Analyses) and ANOSIM (Analysis of Similarities) were performed. Results: A total of 918 individuals, which correspond to 39 taxa distributed in 22 families, were recorded in samples from NMPA and BB slope, mainly epibenthic or associated with the large corals collected. Ampharete kerguelensis McIntosh, 1885; Hyalinoecia artifex Verrill, 1880; Idanthyrsus macropaleus (Schmarda, 1861); Laetmonice producta Grube, 1877; Onuphis pseudoiridescens Averincev, 1972; Pista mirabilis McIntosh 1885 and Terebellides malvinensis Bremec & Elias, 1999 constitute new records for Burdwood Bank. A similar polychaete assemblage characterized the three areas of NMPA and slope locations, while H. artifex characterized locations at the NW deepest slope of the bank. Conclusions: These results indicate strong connections between the fauna collected at NMPA and the polychaetes assemblage in other Magellan areas dominated by soft bottoms. The biogeographic importance of the BB as connection for benthic polychaete species between South America and the Antarctic Peninsula merits future investigation. Introducción: La primera Área Marina Protegida de mar abierto (no costera) en Argentina, llamada “Namuncurá I” (AMPN), fue creada en 2013 en el Banco Burdwood (BB), una plataforma sumergida ubicada unos 200 km al sur de las Islas Malvinas y 150 km al Este de la Isla de los Estados. En el Océano Atlántico SO. El área comprende tres diferentes áreas de manejo: la central (“el núcleo”, con protección estricta, solo Control y actividades de monitoreo), rodeada por un área “de amortiguación” (solo actividades autorizadas, como investigación científica) y un área externa de “transición” (se contemplan actividades productivas y extractivas en el Plan de Manejo). Más allá del área de transición, el talud y las áreas adyacentes no presentan medidas de protección. Objetivos: proporcionar un inventario de poliquetos colectados durante 2016 y 2017 en el Núcleo (98 m de profundidad), de Amortiguación (128 m), de Transición (133 m-189 m) y Talud (220 m-798 m). Métodos: las muestras fueron obtenidas con una red de arrastre para caracterizar las asociaciones faunísticas y para compararlas con otras áreas Magallánicas. Análisis de Escalamiento Multidimensional y de agrupamiento aglomerativo jerárquico fueron aplicados a una matriz de similaridad de Bray-Curtis para determinar las asociaciones de poliquetos en el AMP – Talud del BB y región Magallánica, respectivamente. Resultados: Un total de 918 individuos, que corresponden a 39 taxones distribuidos en 22 familias, fueron registrados en las muestras del AMPN y talud del BB, mayormente epibentónicos o asociados a grandes corales. Ampharete kerguelensis McIntosh, 1885; Hyalinoecia artifex Verrill, 1880; Idanthyrsus macropaleus (Schmarda, 1861); Laetmonice producta Grube, 1877; Onuphis pseudoiridescens Averincev, 1972; Pista mirabilis McIntosh 1885 y Terebellides malvinensis Bremec & Elias, 1999 constituyen nuevos registros para el Banco Burdwood. Un ensamble de poliquetos similar caracteriza a las tres áreas del AMPN y talud, mientras que H. artifex caracteriza los sitios más profundos del talud del banco. Conclusiones: Estos resultados indican una fuerte conexión entre la fauna colectada en el NMPA y los ensambles de poliquetos de sustratos blandos de otras áreas Magallánicas. La importancia biogeográfica del BB como una conexión entre Sudamérica y la Península Antártica justifican futuras investigaciones.

Genus Terebellides Sars, 1835 Type species: Terebellides stroemii Sars, 1835, Published as part of Lavesque, Nicolas, Hutchings, Pat, Daffe, Gullemine, Nygren, Arne & Londo��o-Mesa, Mario H., 2019, A revision of the French Trichobranchidae (Polychaeta), with descriptions of nine new species, pp. 151-190 in Zootaxa 4664 (2) on page 157, DOI: 10.11646/zootaxa.4664.2.1, http://zenodo.org/record/3384444, {"references":["Sars, M. (1835) Beskrivelser og Iagttagelser over nogle maerkelige eller nye i Havet ved den Bergenske Kyst Levende Dyr af Polypernes, Acalephernes, Radiaternes, Annelidernes og Molluskernes classer, med en kort Oversigt over de hidtil af Forfatteren sammesteds fundne Arter og deres Forekommen. T. Hallager, Bergen, 81 pp. https: // doi. org / 10.5962 / bhl. title. 13017"]}

Terebellides bonifi n. sp. Figures 3–4, Table 2 Type material: Holotype: MNHN-IA-TYPE 1859, gravid, incomplete, Mediterranean Sea, Gulf of Lion, A90, 42°32’39”N, 3°16’03”E, 90 m depth, April 2018. Paratypes: MNHN-IA-TYPE 1860, one specimen, complete (posterior part used for molecular analysis), Mediterranean Sea, Gulf of Lion, A90, 42°32’39”N, 3°16’03”E, 90 m depth, April 2018; MNHN-IA-TYPE 1861, one specimen, complete, Mediterranean Sea, Gulf of Lion, A90, 42°32’39”N, 3°16’03”E, 90 m depth, April 2018. MNHN-IA-TYPE 1862, one specimen, gravid, complete, Mediterranean Sea, Gulf of Lion, A90, 42°32’39”N, 3°16’03”E, 90 m depth, April 2018, mounted for SEM. All type specimens fixed with 96% alcohol. Description. Relatively large species, with incomplete holotype 29.8 mm long (22.2– 24.3) and 1.8 mm (1.8–2 mm). Body tapering posteriorly with segments becoming increasingly shorter and more compacted towards pygidium. Prostomium compact; eyespots absent; large upper lip surrounding mouth with many buccal tentacles (Fig. 3 B–D). Buccal tentacles of 2 types, uniformly cylindrical and with expanded tips, spatulate (Fig. 3 C–D). Lower lip forming an expanded structure below upper lip (Fig. 2B, D). SG 1 and 2 short, only visible ventrally; following segments with lobes as ventral collars (Fig. 2B). Lateral lappets on SG 3–6 (TC 1–4), continuing ventrally in TC 1–5, largest on TC 1 and declining in size posteriorly (Figs 3B, D & 4A). Conspicuous dorsal rounded projection on TC 1–3 (Figs 3B, D & 4A). Presence of oval glandular lateral region on TC 3 (Fig. 3D). Branchiae arising as a single structure from TC 1, reaching TC 4 (TC 3), consisting of single elongate and annulated stalk placed mid-dorsally (Figs 3 A–D & 4A), 2 pairs of lobes, fused for about 1/2 of length, lower pair thinner. Upper lobes with about 45 tightly packed lamellae (Figs 3 A–D & 4A–B). Anterior lamellae of each branchia with short conical papillae, visible under stereomicroscope (Figs 3C & 4 A–B). Distal region of upper lobes with short projections, lower lobes with long projections (Fig. 3 C–D). Anterior branchial projection (5 th lobe) present (Figs 3 A–B, D & 4A). Eighteen pairs of thoracic notopodia (SG 3–20). First notopodium slightly longer than subsequent notopodia; notochaetae from TC 1 about same size as ones from subsequent notopodia, and transversally aligned (Fig. 3D). All notochaetae simple capillaries, arranged in two rows. Neuropodia present as sessile pinnules from TC 6 (SG 8) to pygidium; uncini arranged in single rows from TC 7. First thoracic neuropodium (TC 6) provided with 5–7 sharply bent acute tipped, geniculate chaetae. All subsequent thoracic neuropodia with about 12–15 uncini per torus arranged in one irregular row. Uncini as shafted denticulate hooks provided with long, thin and pointed main fang. Three or four teeth above the main fang, surmounted by a row of three to five short denticles and an upper crest of several minute denticles (Fig. 4C). About 32 abdominal neuropodia as erect pinnules, paddle-shaped with entire margin provided with about 40 uncini; uncini with four pointed teeth above main fang, surmounted by a row of three short pointed teeth and an upper crest of minute teeth (Fig. 4D). Two pairs of globular nephridial papillae, located latero-posteriorly to base of each notopodium of TC 4 and TC 5. Pygidium crenulated, as a funnel-like depression. Methyl green staining pattern. First 4 TC stain solid; TC 5 and TC 11 with distinct stripes; ventral faces of lobes stained dark blue; glandular region blue (Fig. 3 C–D). Etymology. The species is named after Paulo Bonifácio, alias Bonif, for his friendship and for being an excellent and fascinating worms’ teacher to NL. Habitat. Mud, about 90 m depth. Type locality. Western Mediterranean Sea (Gulf of Lion), France (Fig. 1). Distribution. Only known from type locality. Remarks. Terebellides bonifi n. sp. is characterized by the papillar projections pointing over the edge of the branchial lamellae. By this characteristic, T. bonifi n. sp. is similar to T. europea n. sp., T. gentili n. sp., T. lilasae n. sp., T. resomari n. sp. and T. stroemii from Adriatic Sea (Parapar et al. 2013) (see T. lilasae n. sp. remarks). Among these species, T. bonifi n. sp. is similar to T. europea n. sp., in having papillar projections on anterior lamellae only, but differs from this species by the presence of an oval glandular region on TC 3 (instead of undulating one for T. europea n. sp.) and presence of rounded conspicuous dorsal projection on TC 1–3. The presence of oval glandular region T. bonifi n. sp. is similar of that present in T. lilasae n. sp. and T. stroemii from Adriatic. However, these species differ by the absence of papillar projections on posterior branchial lamellae in T. bonifi n. sp. (presence on most of the lamellae T. lilasae n. sp. and T. stroemii from Adriatic), and by the shape of papillar projections, conical for T. bonifi n. sp., and rounded for T. lilasae n. sp. and T. stroemii from Adriatic. Molecular results, based on material available for this study, show that T. bonifi n. sp. appears to be absent from Northern waters (Fig. 23).

Terebellides ceneresi n. sp. Figures 5–6, Table 2 Type material: Holotype: MNHN-IA-TYPE 1863, complete, Northeast Atlantic Ocean, Bay of Biscay, P34, 43°33’31’’N, 1°43’49’’W, 112 m depth, May 2018; Paratypes: MNHN-IA-TYPE 1864, one specimen, complete, Northeast Atlantic Ocean, Bay of Biscay, P36, 43°34’58’’N, 1°42’01’’W, 126 m depth, May 2018; AM W.51400, one specimen, complete, Northeast Atlantic Ocean, Bay of Biscay, P37, 43°33’31”N, 1°43’49”W, 129 m depth, May 2018; MNHN-IA-TYPE 1865, one specimen, complete, Northeast Atlantic Ocean, Bay of Biscay, P36, 43°35’0”N, 1°42’02”W, 125 m depth, May 2018. Additional material examined: SMA _BAN_11, one specimen, complete (posterior part used for molecular analysis), Mediterranean Sea, Gulf of Lion, A90, 42°32’39”N, 3°16’03”E, 90 m depth, April 2018, mounted for SEM; SMA _BAN_20, one specimen, complete, Mediterranean Sea, Gulf of Lion, Ibis 183, 42°30’30”N, 3°09’06”E, 40 m depth, December 2018; SMA _BAN_03, one specimen, complete, gravid, Mediterranean Sea, Gulf of Lion, A90, 42°32’40”N, 3°16’05”E, 90 m depth, August 2010, mounted for SEM; SMA _BR_34, incomplete, Northeast Atlantic Ocean, Brittany, Bay of Brest, ZC, 48°18’55” N, 4°21’53” W, 5 m depth, May 2018; AM W.51401, one specimen, complete, gravid, Mediterranean Sea, Gulf of Lion, A90, 42°32’40”N, 3°16’05”E, 90 m depth, August 2010; AM W.51402, one specimen, incomplete, Mediterranean Sea, Gulf of Lion, A90, 42°32’39”N, 3°16’03”E, 90 m depth, April 2018. Description. Small species, holotype 14.2 mm long (14.2–16.5 mm) and 1.1 mm (0.8–1.1 mm). Body tapering posteriorly with segments becoming increasingly shorter and more compacted towards pygidium. Prostomium compact; eyespots absent; large upper lip surrounding mouth with many buccal tentacles (Fig. 5B, D). Buccal tentacles of 2 types, short cylindrical and very long tentacles, spatulate (Fig. 5D). Lower lip forming an expanded structure below upper lip. SG 1 and 2 short, only visible ventrally; following segments with lobes as ventral collars (Fig. 5D). Lateral lappets on SG 3–7 (TC 1–5), continuing ventrally, largest on TC 1–4 and declining in size posteriorly (Figs 5 A–C). No conspicuous dorsal rounded projection on anterior chaetigers. Glandular lateral region absent on TC 3 (Fig. 5C). Branchiae arising as a single structure from TC 1, reaching TC 7 (TC 8), consisting of a single elongate and annulated stalk placed mid-dorsally (Figs 5 B–C & 6A), two pairs of lobes, not fused, lower pair narrower (Fig. 6A). Upper lobes with about 25 tightly packed lamellae (Figs 5A & 6A). Both sides of branchial lamellae provided with several parallel rows of cilia and tufts of cilia on outer edge (Fig. 6 A–B). Branchiae provided without any papillar projections pointing over the edge of the branchial lamellae (Fig. 6B). Distal region of lower lobes with short terminal pointed projections (Fig. 6A). Anterior branchial projection (5 th lobe) absent (Fig. 6A). Eighteen pairs of thoracic notopodia (SG 3–20). First notopodium on TC 1 well-developed, same size as on subsequent notopodia, notopodia placed in a straight line; notochaetae from TC 1 much smaller (or absent) than following notochaetae (Figs 5 A–C & 6A). All notochaetae simple capillaries, arranged in two rows. Neuropodia present as sessile pinnules from TC 6 (SG 8) to pygidium; uncini arranged in single rows from TC 7. First thoracic neuropodium (TC 6) provided with about five to six sharply bent acute tipped, geniculate chaetae. All subsequent thoracic neuropodia with 7–10 uncini per torus arranged in one irregular row. Uncini as shafted denticulate hooks provided with long, thin and pointed main fang appearing bent terminally giving an ‘eagle head’ appearance (Fig. 6C). Three or four teeth above the main fang, surmounted by a row of four to five short denticles and an upper crest of several smaller denticles (Fig. 6C). About 30 abdominal neuropodia as erect pinnules paddle-shaped with entire margin provided with about 20 uncini; each with four to six pointed teeth above main fang, surmounted by a row of four or five short pointed teeth and an upper crest of minute teeth (Fig. 6D). Nephridial papillae not seen. Pygidium blunt, as a funnel-like depression. Methyl green staining pattern. First 10 TC stain solid, except TC 4 much lighter (Fig. 5D); TC 11 and TC 12, stain with distinct stripes, fading towards posterior thoracic region (without staining, first four chaetigers slightly lighter than following ones) (Fig. 5D). Etymology. The species is named in honour of the CNRS (French National Center for Scientific Research) that celebrates, in 2019, 80 years since its foundation. Habitat. Mud to sandy mud, from 90 to 140 m depth, coastal maerl (rhodolith) beds. Type locality. Near Capbreton Canyon, Bay of Biscay, Northeast Atlantic Ocean, France. Distribution. Northeast Atlantic Ocean (Bay of Biscay), Western Mediterranean Sea (Gulf of Lion), France (Fig. 1). Remarks. Terebellides ceneresi n. sp. is very similar to specimens of T. gracilis from the Adriatic Sea (Parapar et al. 2013), in being of small size, without rounded dorsal projection or glandular region in CH 3, the absence of notochaetae on first chaetiger in smaller specimens and short notochaetae on first chaetiger for larger ones and in having the same very distinctive MG staining pattern. The two species differ only by the presence of an ‘eagle head’ appearance of thoracic uncini of T. ceneresi. However, T. ceneresi n. sp. is clearly different from the holotype of T. gracilis (Parapar et al., 2011). Indeed, T. gracilis is a larger species (32 mm vs 16 mm for gravid specimens of T. ceneresi n. sp.), with a 5 th lobe present (absent in T. ceneresi n. sp.), with up to 22 uncini in thoracic chaetigers (instead of 8 in T. ceneresi n. sp.), with posterior region of lobes with pointed projections (instead of absence or very short projections in T. ceneresi n. sp.), with MG compact colouration from CH 1 to CH 10 (instead of whitish bands from CH 1 to CH 4, especially on CH 4 in T. ceneresi n. sp.) (Table 2). Molecular results, based on material available for this study, show that T. ceneresi n. sp. appears to be absent from Northern waters (Fig. 23).

Trichobranchidae from French waters are revised based on material available in French marine stations and newly collected specimens. This research is the first part of the “Spaghetti Project” aiming to revise French species of terebellids and trichobranchids. It confirms the absence of the so-called cosmopolitan species Terebellides stroemii from French waters, and describes eight new species of Terebellides: T. bonifi n. sp., T. ceneresi n. sp., T. europaea n. sp., T. gentili n. sp., T. gralli n. sp., T. lilasae n. sp., T. parapari n. sp. and T. resomari n. sp. and one species of Trichobranchus: T. demontaudouini n. sp. using both morphological and molecular tools. An identification key for all European species of Trichobranchidae is provided.

A large collection of mesoparasitic copepods from polychaete hosts collected in northern European waters was examined. The term mesoparasitic refers to highly transformed copepods where the adult female attaches by embedding part of its body in the host. Representatives of five known familes were found and a new family is established. A single new species, Bradophila minuta sp. nov., was described in the family Bradophilidae. It occurred exclusively on the flabelligerid Diplocirus glaucus (Malmgren, 1867). Two genera of the family Herpyllobiidae were represented: Herpyllobius Steenstrup & Lütken, 1861 and Eurysilenium M. Sars, 1870. Herpyllobius arcticus Steenstrup & Lütken, 1861 was found on at least five different polynoid hosts, two of which, Harmothoe fragilis Moore, 1910 and Antinoe sp., were new host records. A new species, H. cluthensis sp. nov. was described from Malmgrenia species in Scottish waters. The large species, Herpyllobius cordiformis Lützen, 1964, was collected in Arctic waters from Eunoe cf. oerstedi. It is the first report of this parasite in Europe. The common parasite H. polynoes (Krøyer, 1864) was found on six different polynoid hosts, three of which, Harmothoe bifera, Malmgreniella mcintoshi Tebble & Chambers, 1982 and Eunoe ?barbata are new host records. Eurysilenium truncatum M. Sars, 1870 was collected from Eucranta villosa Malmgren, 1866, Eunone sp., and Gattyana cirrhosa (Pallas, 1766). The material from Eucranta villosa caught at 72.6ºN comprises both a new host record and is the most northerly report of this parasite. Specimens of Eurysilenium which differed from E. truncatum in a number of features were found on Harmothoe fragilis and H. impar (Johnston, 1839). A new family, the Pholoicolidae, is established to accommodate Pholicola chambersae gen. et sp. nov., parasitic on Pholoe pallida Chambers, 1985. The family Phyllodicolidae was represented by all three of its known species: Phyllodicola petiti (Delamare Deboutteville & Laubier, 1960), Cyclorhiza eteonicola Heegaard, 1942 and C. megalova Gotto & Leahy, 1988. The former was found on Eumida ockelmanni Eibye-Jacobsen, 1987, a new host record. A single ovigerous female of C. eteonicola was collected from a new host, Eteone spetsbergensis Malmgren, 1865. Cyclorhiza megalova was common on Eteone longa (Fabricius, 1780) and E. longa/flava complex. A rich diversity of members of the family Saccopsidae was found, including three known species of Melinnacheres M. Sars, 1870 plus nine new species placed in four new genera. Melinnacheres was represented by M. ergasiloides M. Sars, 1870, M. steenstrupi Bresciani & Lützen, 1961 and M. terebellidis Levinsen, 1878. Melinnacheres ergasiloides was found on Melinna elizabethae McIntosh, 1914, M. steenstrupi on members of the Terebellides stroemi-complex and T. atlantis Williams, 1984, while M. terebellidis was found on the T. stroemi-complex and on T. shetlandica Parapar, Moreira & O'Reilly, 2016. A new genus, Trichobranchicola gen. nov., was established to accommodate T. antennatus gen. et sp. nov., a parasite of Trichobranchus sikorskii Leontovich & Jirkov in Jirkov, 2001, T. glacialis Malmgren, 1866 and Trichobranchus sp. The second new genus, Lanassicola gen. nov., was established to accommodate the type species, Lanassicola arcticus gen. et sp. nov. parasitic on Lanassa venusta (Malm, 1874), plus two additional species, L. bilobatus gen. et sp. nov. on Lanassa nordenskjoeldi Malmgren, 1866, and L. dorsilobatus gen. et sp. nov. on Proclea graffii (Langerhans, 1884). A new subfamily, Euchonicolinae, was established within the Saccopsidae to accommodate two new genera, Euchonicola gen. nov. and Euchonicoloides gen. nov. The type species of Euchonicola gen. nov. is E. caudatus gen. et sp. nov., a parasite of Euchone sp., and it includes two other species, E. linearis gen. et sp. nov. on Chone sp., and E. parvus gen. et sp. nov. on Euchone sp. The type species of Euchonicoloides gen. nov. is E. elongatus gen. et sp. nov. found on a host belonging to the genus Euchone, and it also includes Euchonicoloides halli gen. et sp. nov. from Jasmineira caudata Langerhans, 1880. Four species of the family Xenocoelomidae were found: Xenocoeloma alleni (Brumpt, 1897), X. brumpti Caullery & Mesnil, 1915, X. orbicularis sp. nov. and Aphanodomus terebellae (Levinsen, 1878). Xenocoeloma alleni was found on four different species of Polycirrus and on Amaeana trilobata (M. Sars, 1863) and X. brumpti was found on Polycirrus norvegicus Wollebaek, 1912. Xenocoeloma orbicularis sp. nov. occurred only on Paramphitrite birulai (Ssolowiew, 1899). Aphanodomus terebellae was found on three hosts, only one of which, Leaena abranchiata was new.

Key to all described species of Terebellides from the Northwestern Pacific 1. Branchial lobes free of each other........................................................................ 2 - Branchial lobes at least partially fused along their length..................................................... 3 2. Acicular uncini present on TC6 and TC7, lower lip greatly expanded, branchial lobes equal in size................................................................................................ Terebellides intoshi Caullery, 1915 - Acicular uncini on TC6 only, lower lip not expanded, branchial lobes differ in size................................... ............................................................... Terebellides lineata Imajima & Williams, 1985 3. Acicular uncini present on TC5 and TC6............................................. Terebellides ectopium n. sp. - Acicular uncini on TC6 only.............................................................................4 4. Branchia anteriorly prolonged (5th lobe)................................................................... 5 - Branchia not anteriorly prolonged......................................................................... 6 5. Notopodia of TC1 and TC2 well developed, lateral lappets until TC6.................... Terebellides kobei Hessle, 1917 - Notopodia of TC1 and TC2 markedly less developed than subsequent ones, lateral lappets until TC7..................................................................................................... Terebellides yangi n. sp. 6. Notopodia of TC1 and TC2 well developed......................... Terebellides horikoshii Imajima & Williams, 1985 - Notopodia of TC1 and TC2 markedly less developed than subsequent ones........................................ 7 7. Lateral lappets until TC4 only. Acicular uncini sharply bent with mucronate tips..................................................................................................... Terebellides brevis Imajima & Williams, 1985 - Lateral lappets until TC5 only. Acicular uncini sharply bent without mucronate tips................................. 8 8. Length ratio of thorax and abdomen>1.0, thoracic neuropodia with few (less than 25) uncini per torus, ��40 abdominal seg- ments................................................................... Terebellides guangdongensis n. sp. - Length ratio of thorax and abdomen almost 0.5, thoracic neuropodia with 40 or more uncini per torus, 45-50 abdominal seg- ments.................................................................... Terebellides japonica Moore, 1903, Published as part of Zhang, Jinghuai & Hutchings, Pat, 2018, Taxonomy and distribution of Terebellides (Polychaeta: Trichobranchidae) in the northern South China Sea, with description of three new species, pp. 387-411 in Zootaxa 4377 (3) on pages 409-410, DOI: 10.11646/zootaxa.4377.3.4, http://zenodo.org/record/1164508, {"references":["Caullery, M. (1915) Sur les Terebellides Malmgren du Siboga et les Terebelliens voisins. Bulletin de la Societe Zoologique de France, 40, 111 - 116.","Imajima, M. & Williams, S. J. (1985) Trichobranchidae (Polychaeta) chiefly from the Sagami and Suruga Bays, collected by the R / V Tansei-Maru (cruises KT- 65 - 76). Bulletin of the National Science Museum, Tokyo, 11 (1), 7 - 18.","Hessle, C. (1917) Zur Kenntnis der terebellomorphen Polychaeten. Zoologiska Bidrag fran Uppsala, 5, 39 - 258.","Moore, J. P. (1903) Polychaeta from the coastal slope of Japan and from Kamchatka and Bering Sea. Proceedings of the Academy of Natural Sciences, Philadelphia, 55, 401 - 490."]}

Terebellides guangdongensis n. sp. Figures 2���5 Material examined. Holotype. MBM 286009 in IOCAS, Guangdong, Nanao Island, South China Sea, 23.4982��N 117.2546��E, 15.0 m, mud, Sep 2015. Paratypes. MBM286010 (2 specimens), MBM286024 (1 specimen mounted for SEM) in IOCAS: Guangdong, Nanao Island, South China Sea, 23.4982�� N 117.2546�� E, 15.0 m, mud, Sep 2015; MBM286011 (3 specimens) in IOCAS: Guangdong, Daya Bay, South China Sea, 22.6078�� N 114.7286�� E, 12.0 m, mud sand, Sep 2013; MBM286012 (2 specimens), MBM286021 (4 specimens) in IOCAS: Guangdong, Daya Bay, South China Sea, 22.5764�� N 114.6839�� E, 17.0 m, mud, Jun 2015; MBM286013 (1 specimen), MBM286015 (1 specimen) in IOCAS: Guangdong, Daya Bay, South China Sea, 22.7158�� N 114.6644�� E, 9.0 m, mud, Jun 2015; MBM286014 (1 specimen) in IOCAS: Zhanjiang, Guangdong, Beibu Gulf, South China Sea, 20.4099�� N 109.7840�� E, 17.5 m, mud, May 2016; MBM286016 (4 specimens) in IOCAS: Maoming, Guangdong, the coast of Yuexi, South China Sea, 21.2500�� N 111.1500�� E, 19.0 m, mud, Jun 2016; MBM286017 (1 specimen) in IOCAS: Guangdong, Daya Bay, South China Sea, 22.6083�� N 114.7289�� E, 7.5 m, silt, Jun 2015; MBM286018 (5 specimens) in IOCAS: Guangdong, Daya Bay, South China Sea, 22.6675�� N 114.6642�� E, 10 m, silt, Aug 2016; MBM286019 (1 specimen) in IOCAS: Guangdong, Daya Bay, South China Sea, 22.7050�� N 114.7217�� E, 9.0 m, mud, Aug 2016; MBM286020 (1 specimen) in IOCAS: Shanwei, Guangdong, the coast of Yuedong, South China Sea, 22.2888�� N 115.1530�� E, 40.0 m, mud, Aug 2015; MBM286022 (2 specimens) in IOCAS: Guangdong, Daya Bay, South China Sea, 22.6247�� N 114.6719�� E, 14 m, mud, Jun 2015; MBM286023 (1 specimen) in IOCAS, P20161225001 (2 specimens) in SCSEM: Guangdong, Daya Bay, South China Sea, 22.5750�� N 114.5186�� E, 14 m, mud, Jun 2015; MBM286025 (1 specimen) in IOCAS: Guangdong, Daya Bay, South China Sea, 22.6672�� N 114.6639�� E, 10.5 m, silt, Jun 2015. Description (Based on both holotype and paratypes). Holotype complete, 29.3 mm in length and 0.3���2.6 mm in width (from posterior end to anterior chaetigers (excluding chaetae) respectively), with distinct demarcation between thorax and abdomen; with 39 abdominal segments; body tapering posteriorly with segments. Dorsum and ventrum smooth, colour pale to reddish in preserved specimens. Buccal tentacles of two types on dorsal margin of large tentacular membrane, uniformly tapered and with expanded tips (Figs 2A���B & 3A���B, H). Prostomium compact almost completely hidden by tentacular membrane. Eyespots absent. Peristomium consisting of expanded lower lip which forms an elongate rectangular structure and upper lip often covered by lower lip and tentacular membrane (Figs 2A���B & 3A���B). Segments 1���2 with small lateral lappets and inconspicuous ventral collar (Figs 2A���B; 3B���C & 5A���C). Segments 3���7 with distinct lateral lappets, largest on segment 4; forming thickened ventral membranous collars (ventral lobes) on anterior margins of segments 3���7, lobes progressively shorter from segment 4 onwards; ventral lobes of segment 3 with undulating margins in the middle, others with smooth margins (Figs 2A���B; 3A���B & 5A���B). Thoracic chaetiger 2 (segment 4) with a nephridial papilla at base of notopodia (Figs 3B���C & 5C). Segment 2 with a dorsal lobe anterior to branchial stem (Figs 3B���C & 5C). Lateral lappets without projections (Figs 2A; 3B & 5C). Ventral glandular bands and glandular areas around parapodia absent. Branchia as single elongate structure dorsally on segments 2���4, consisting of two pairs of posterior lobes (BL1���2 on the outside and BL 3���4 in the middle) and pair of anterior lobes, lobes composed of tightly packed lamellae (Figs 2C; 3D & 5B). Anterior lobes (BL5���6) fused completely, and very short about 1/12 posterior lobes. Posterior lobes fused for about 3/5 their length. BL1���2 as long as BL3���4. BL1���2 and BL5���6 with large lamellae, broad almost 3 times more than BL3���4; lamella of BL1���2 and BL3���4 with longitudinal ridges; outer edges of lamellae with a row of small rounded papilla; inside edges of lamellae smooth; without cilia (Fig. 3D���G); BL3���4 with small lamellae, without distal tip. Thorax with 20 segments without dorsal hump. Notopodia 18 pairs, present on segments 3���20 (chaetigers 1��� 18). First two pairs smaller and inserted more dorsally to subsequent ones; first one markedly reduced with shorter and finer chaetae, notochaetae appearing to arise from body wall (Figs 2A; 3A���C; 4A���B & 5C). Chaetae arranged in 2 tiers, lower tier with finely pointed chaetae and upper tier with narrowly���winged chaetae; chaetae of lower tier finer and about 1/2 length of those upper tier (Figs 2G���H & 4A���B, E���G). Neuropodia beginning from segment 8 (chaetiger 6), and present on all subsequent segments. Thoracic neuropodia as sessile pinnules. First neuropodia with geniculate acicular hooks (holotype right 6 and left 7); geniculate hooks arranged in single row throughout with pointed tips and weakly bent, and gradually decreasing in size from dorsal to ventral; the smaller geniculate hooks being sharply bent (Figs 2E & 4C���D). Subsequent thoracic neuropodia with one row or partial double rows of 23���25 long-handled uncini per torus; uncini with main fang and several rows of secondary teeth, with 3���4 large teeth in the first row (Figs 2F & 4H���I). Abdomen with 39 segments with length gradually decreasing posteriorly. Abdominal neuropodia as foliaceous pinnules with about 30 avicular uncini; arranged in single row (Fig. 4J). Abdominal uncini with strongly crested head, covered with numerous small and scale-like teeth (Figs 2I & 4K���L). Pygidium blunt without appendages (Figs 2D & 5E). The methyl green staining similar to pattern 1 of Sch��ller & Hutchings (2010), compact green colour on the first five segments, then developing into striped pattern (Fig. 5A, D). Margin of lower lip with white stripe on peristomium. Thoracic stripes gradually fade from segment 6, and disappearing by about segment 15. Green bands present on lateral thorax and abdominal ventrum. Additionally, staining on thoracic notopodia, base of posterior abdominal neuropodia and ventrum of tips of posterior branchial lobes. Lamellae of branchial lobes without staining. Variability. Complete individuals ranging from 2.3���29.2 mm in length, 0.2���2.6 mm in width of anterior chaetigers excluding the chaetae and 18���40 abdominal segments. The large specimens with greater width and more abdominal segments than smaller ones (Fig. 6A). The length ratio of thorax and abdomen (LRTA) ranging from 1.2���6.2, showing large specimens possibly with a smaller LRTA and relatively long abdomen (Fig. 6B). Geniculate hooks ranging from 5���7 in number, with numbers appearing to increase with body size. Thoracic neuropodia with less than 15 (smaller specimens) to 25 uncini per torus on larger specimens, suggesting that the number increases with size of individual and presumably age. Remarks. Terebellides guangdongensis n. sp. is characterised by the following morphological characters: one branchia has two pairs of posterior lobes and pair of anterior lobes not distinctly prolonged; all branchial lobes have densely packed lamellae; BL1���2 are as long as BL3���4, and broader than BL3���4; thoracic chaetigers of which the first five have lateral lappets, without conspicuous projections; first notopodia are strongly reduced, and have shorter and finer chaetae compared to subsequent ones; only chaetiger 6 has geniculate hooks. Terebellides guangdongensis n. sp. is very similar to Terebellides californica Williams, 1984, Terebellides horikoshii Imajima & Williams, 1985 and Terebellides japonica Moore, 1903 in that they all have one branchia with six lobes which include a pair of anterior lobes completely fused lacking marked elongation and two pairs of posterior lobes partially fused along their length; all branchial lobes with densely packed lamellae; lateral lappets present on chaetigers 1���5 and chaetiger 6 with geniculate hooks only. Terebellides guangdongensis n. sp. can be distinguished from Terebellides horikoshii and Terebellides japonica by thoracic neuropodia having single or partial double rows of few (less than 25) uncini per torus, but the latter two species have double rows of 40 or more uncini per torus. Terebellides horikoshii and Terebellides californica both have well developed notopodia 1 and 2, compared to Terebellides guangdongensis n. sp. which has poorly developed notopodia 1 and 2, especially the first one. The abdomen of Terebellides japonica is longer than the thorax with an LRTA of almost 0.5, but the LRTA of Terebellides guangdongensis n. sp. range is from 1.2���6.2. Terebellides guangdongensis n. sp. is also very similar to Terebellides hutchingsae Parapar, Moreira & Martin, 2016. These two species can be distinguished by the characters of branchiae and chaetae of thoracic neuropodia. BL1���2 and BL3���4 of Terebellides guangdongensis n. sp. are of equal length and partially fused lobes, whereas BL1���2 and BL3���4 of Terebellides hutchingsae are free, and BL1���2 longer than BL3���4. Neuropodia of Terebellides guangdongensis n. sp. have weakly bent geniculate chaetae on TC6 and 23���25 long-handled uncini per torus in subsequent thoracic chaetigers. In contrast neuropodia of Terebellides hutchingsae have sharply bent geniculate chaetae on TC6 and relative few (8���10) uncini per torus in subsequent ones. Distribution. Known only from Shantou waters, Guangdong of the northern South China Sea (Fig. 1). Habitat. Found in muddy substrates in shallow water (7.5���40 m depths). Etymology. The specific name guangdongensis is derived from guang dong, latinized Chinese characters for the locality, which refers to the type locality in the Guangdong Province waters., Published as part of Zhang, Jinghuai & Hutchings, Pat, 2018, Taxonomy and distribution of Terebellides (Polychaeta: Trichobranchidae) in the northern South China Sea, with description of three new species, pp. 387-411 in Zootaxa 4377 (3) on pages 389-396, DOI: 10.11646/zootaxa.4377.3.4, http://zenodo.org/record/1164508, {"references":["Schuller, M. & Hutchings, P. A. (2010) New insights in the taxonomy of Trichobranchidae (Polychaeta) with description of a new Terebellides species from Australia. Zootaxa, 2395, 1 - 16.","Williams, S. J. (1984) The status of Terebellides stroemii (Polychaeta; Trichobranchidae) as a cosmopolitan species, based on a worldwide morphological survey, including description of new species. In: Hutchings, P. A. (Ed.), Proceedings of the First International Polychaete Conference, Sydney, Australia, 1984. The Linnean Society of New South Wales, Sydney, pp. 118 - 142.","Imajima, M. & Williams, S. J. (1985) Trichobranchidae (Polychaeta) chiefly from the Sagami and Suruga Bays, collected by the R / V Tansei-Maru (cruises KT- 65 - 76). Bulletin of the National Science Museum, Tokyo, 11 (1), 7 - 18.","Moore, J. P. (1903) Polychaeta from the coastal slope of Japan and from Kamchatka and Bering Sea. Proceedings of the Academy of Natural Sciences, Philadelphia, 55, 401 - 490.","Parapar, J., Moreira, J. & Martin, D. (2016) On the diversity of the SE Indo-Pacific species of Terebellides (Annelida; Trichobranchidae), with the description of a new species. PeerJ, 4, e 2313. https: // doi. org / 10.7717 / peerj. 2313"]}

Terebellides ectopium n. sp. Figures 13���16 Material examined. MBM 286026 in IOCAS, Zhanjiang, Guangdong, Baibu Gulf, north South China Sea, 20.4099�� N 109.7840�� E, 17.5 m, mud, May 2016. Paratype. MBM 286027 (1 specimen, on SEM stub) in IOCAS, collected from same site as holotype. (Catalog numbers in IOCAS are tentative, which will be changed after the specimens are deposited in IOCAS before this manuscript is published in its final form.) Description (Based on both holotype and paratypes). Holotype complete, 22.4 mm in length and 0.3���2.2 mm in width (from posterior end to anterior chaetigers (excluding chaetae) respectively), with distinct demarcation between thorax and abdomen; with 27 abdominal segments; body tapering posteriorly with segments (Fig. 16A��� B). Dorsum and ventrum smooth, colour pale to reddish in preserved specimens. Buccal tentacles of two types on dorsal margin of large tentacular membrane, uniformly tapered and with expanded tips (Figs 13A���B & 14B���D). Prostomium compact which is almost completely hidden by expanded tentacular membrane. Eyespots absent. Peristomium consisting of expanded lower lip which forms an elongate rectangular structure and upper lip often covered by lower lip and tentacular membrane (Figs 13A���B; 14C���D & 16A). Segments 1���2 with small lateral lappets and inconspicuous ventral collar; segments 2 with a dorsal lobe and pair of dorsal cirri at base of branchia (Figs 13A & 14B���D). Segments 3���7 with distinct lateral lappets, largest on segment four; forming thickened membranous ventral collars on anterior margins of segments 3���7, and lobes progressively shorter from segment 4 onwards; ventral collars of segment 3 with an inverted ���n��� shaped invagination in centre, other segments with smooth ventral collars (Figs 13A���B & 14C). Lateral lappets without conspicuous projection (Figs 13A & 14C���D). Ventral glandular bands and glandular areas around parapodia absent. Branchia as single elongate structure dorsally inserted on segments 2���4, consisting of two pairs of posterior lobes and pair of anterior lobes (Figs 13A; 14D���E & 16A). Anterior lobes (BL5���6) fused completely, and prolonged about 1/4 posterior lobes. Posterior lobes fused for about 2/3 their length. BL1���2 much longer and larger than BL3���4. BL1���2 and BL5���6 with large lamellae, without distal tip; lamella of BL1���2 and BL5���6 with longitudinal ridges, without a row of papilla; BL3���4 with small lamellae and short distal tip (Fig. 14D���F). Thorax with 20 segments without dorsal hump. Notopodia 18 pairs, present on segments 3���20 (thoracic chaetigers 1���18). First two pairs smaller and situated more dorsally than following ones; first one strongly reduced with shorter and finer chaetae, notochaetae almost appearing to arise from body wall (Figs 13A, H; 14B���D, G & 16A). Chaetae arranged in 2 tiers, lower tier with finely pointed chaetae and upper tier with narrowly���winged chaetae; chaetae of lower tier finer and about 2/3 length of those of upper tier (Fig. 15D���H). Neuropodia beginning from segment 7 (chaetiger 5), and present on all subsequent segments. Thoracic neuropodia sessile pinnules. Neuropodia of chaetigers 5���6 with geniculate hooks arranged in single row; geniculate hooks with sharply constricted mucronate tips; ventral geniculate hooks smaller than dorsal ones; neuropodia of chaetiger 5 situated more ventrally than subsequent ones, and with 5 weakly bent geniculate hooks; neuropodia of chaetiger 6 with 5 sharply bent geniculate hooks (Figs 13C���E; 14C; 15A���C & 16C). Neuropodia of thoracic chaetigers 7���13 with one row of 16���18 long-handled uncini per torus; following thoracic neuropodia with partial double rows of 16���19 longhandled uncini per torus; uncini with several rows of secondary teeth above main fang, and 5���7 major teeth of first row (Figs 13F & 15I ���K). Abdomen with 27 segments with length gradually decreasing posteriorly. Abdominal neuropodia as foliaceous pinnules with about 26 avicular uncini; arranged in a single row (Fig. 15L). Abdominal uncini with strongly crested head, covered with numerous small and scale-like teeth (Figs 13G & 15M). Pygidium blunt without appendages (Fig. 16D). The methyl green staining similar to pattern 4 of Sch��ller & Hutchings (2010), compact green colour of the first ten segment, and gradually fading (Fig. 11A���B). Margin of lower lip without white stripe. Following segment 10, segments without green stripes. Posterior abdominal neuropodia weakly stained. Thoracic notopodia, branchial tips and lamellae without staining. Variability. Paratype complete, 19.2 mm in length, 0.3���1.99 mm in width and 25 abdominal segments. Neuropodia with 5 weakly bent geniculate hooks on segment 5; neuropodia with 4 sharply bent geniculate hooks on segment 6. Neuropodia of TC7���18 with one or partial double rows of 16���19 long-handled uncini per torus. As we only have two complete specimens of similar size, we cannot comment on variation of morphological characters. Remarks. Terebellides ectopium n. sp. is easily distinguished from other species by TC5���6 with geniculate hooks with conspicuously constricted mucronate tips; neuropodia of TC5 situated more ventrally than following ones; first two pairs of notopodia are strongly reduced, and have shorter and finer chaetae than subsequent ones; a single branchia with three pairs of branchial lobes, the two pairs of posterior lobes are partially fused along their length, and BL1���2 are much longer and larger than BL3���4, BL5���6 distinctly prolonged for about 1/2 posterior lobes. There are four other species of Terebellides having geniculate hooks in TC5���6, Terebellides akares Hutchings, Nogueira & Carrerette, 2015 (type locality Lizard Island, Australia), Terebellides biaciculata Hartmann-Schr��der, 1992 (type locality French Polynesia), Terebellides bigeniculatus Parapar, Moreira & Helgason, 2011 (type locality Iceland) and Terebellides crux Sch��ller & Hutchings, 2013 (type locality Southern Ocean). Terebellides ectopium n. sp. clearly differs from these species by the geniculate acicular hooks with conspicuously constricted mucronate tips and neuropodia of TC5 situated more ventrally than following ones. The new species can also be distinguished from T. akares which has BL5���6 not prolonged evidently; from T. crux which has free posterior branchial lobes and equal length; from T. biaciculata which has lateral lappets until TC4 and anterior branchial lobes are distinctly larger than posterior lobes; from T. bigeniculatus of which the notopodia of TC1 is similarly developed to subsequent ones. Terebellides ectopium n. sp. is similar to a specimen of Terebellides from the coast of Myanmar in the North Andaman Sea, which Parapar et al. (2016) believe is a new species for the following reasons: BL5���6 is large and about half the length of posterior lobes; TC5 and TC6 are both provided with geniculate acicular chaetae, and neuropodia of chaetiger 5 situated more ventrally than following ones. These characters are the same as Terebellides ectopium n. sp. but as Parapar et al. (2016) only had a single specimen they did not formally describe their specimen. We suggest that this specimen may be synonymous with T. ectopium but until more material becomes available this cannot be confirmed. Distribution. Known only from Beibu Gulf (Fig. 1). Habitat. Found in muddy bottom in shallow water (17.5 m depth). Etymology. The specific name ectopium is derived from English word ectopia, which refers to the different position of geniculate hooks in thoracic chaetigers 5 and 6., Published as part of Zhang, Jinghuai & Hutchings, Pat, 2018, Taxonomy and distribution of Terebellides (Polychaeta: Trichobranchidae) in the northern South China Sea, with description of three new species, pp. 387-411 in Zootaxa 4377 (3) on pages 402-408, DOI: 10.11646/zootaxa.4377.3.4, http://zenodo.org/record/1164508, {"references":["Schuller, M. & Hutchings, P. A. (2010) New insights in the taxonomy of Trichobranchidae (Polychaeta) with description of a new Terebellides species from Australia. Zootaxa, 2395, 1 - 16.","Hutchings, P. A., Nogueira, J. M. M. & Carrerette, O. (2015) Telothelepodidae, Thelepodidae and Trichobranchidae (Annelida, Terebelliformia) from Lizard Island, Great Barrier Reef, Australia. Zootaxa, 4019 (1), 240 - 274. https: // doi. org / 10.11646 / zootaxa. 4019.1.12","Hartmann-Schroder, G. (1992) Zur Polychaeten fauna der Polynesischen Inseln Huahine (Gesellschaftsinseln) und Rangiroa (Tuamotu-Inseln). Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 89, 49 - 84.","Parapar, J., Moreira, J. & Helgason, G. V. (2011) Taxonomy and distribution of Terebellides (Polychaeta, Trichobranchidae) in Icelandic waters, with the description of a new species. Zootaxa, 2983, 1 - 20.","Schuller, M. & Hutchings, P. A. (2013) New species of Terebellides (Polychaeta: Trichobranchidae) from the deep Southern Ocean, with a key to all described species. Zootaxa, 3619 (1), 1 - 45. https: // doi. org / 10.11646 / zootaxa. 3619.1.1","Parapar, J., Moreira, J. & Martin, D. (2016) On the diversity of the SE Indo-Pacific species of Terebellides (Annelida; Trichobranchidae), with the description of a new species. PeerJ, 4, e 2313. https: // doi. org / 10.7717 / peerj. 2313"]}

Benthic ecology monitoring in the northern South China Sea revealed many individuals of the polychaete genus Terebellides (Annelida), which are common in soft sediments in shallow waters (4.5–41.0 m). Three new species of Terebellides are described, including T. guangdongensis n. sp., T. yangi n. sp. and T. ectopium n. sp. Terebellides guangdongensis n. sp. is mainly found in Guangdong waters. Terebellides yangi n. sp. and T. ectopium n. sp. are mainly found in Beibu Gulf. A key to all described species of Terebellides from the Northwestern Pacific is given.

Terebellides yangi n. sp. Figures 7–11 Material examined. Holotype. MBM 286028 in IOCAS: Weizhou Island, Guangxi, Beibu Gulf, South China Sea, 20.6462° N 108.9855° E, 35.0 m, mud, May 2014. Paratypes. MBM286029 and MBM286030 (2 specimens mounted for SEM), MBM286031 (9 specimens), MBM286032 (6 specimens), MBM286033 (5 specimens) in IOCAS: Weizhou Island, Guangxi, Beibu Gulf, South China Sea, 20.6462° N 108.9855° E, 35.0 m, mud, May 2014; MBM286034 (1 specimen) in IOCAS: Guangdong, Daya Bay, South China Sea, 22.6675° N 114.6642° E, 17.5 m, silt, Aug 2016; MBM286035 (3 specimens) in IOCAS: Weizhou Island, Guangxi, Beibu Gulf, South China Sea, 21.0299° N 109.0668° E, 12.0 m, mud, May 2014; MBM286036 (4 specimens) in IOCAS: Weizhou Island, Guangxi, Beibu Gulf, South China Sea, 21.0480° N 108.9509° E, 23.0 m, mud, May 2014. Description (Based on both holotype and paratypes). Holotype complete, 19.2 mm in length and 0.4–2.8 mm in width (from posterior end to anterior chaetigers (excluding chaetae) respectively), with distinct demarcation between thorax and abdomen; with 30 abdominal segments; body tapering posteriorly with segments (Figs 8A & 11A–B). Dorsum and ventrum smooth, colour pale to reddish in preserved specimens. Buccal tentacles of two types on dorsal margin of large tentacular membrane, uniformly tapered and with expanded tips (Figs 7A; 8B–C & 11C). Prostomium compact almost completely hidden by tentacular membrane. Eyespots absent. Peristomium consisting of expanded lower lip which forms an elongate rectangular structure and upper lip often covered by lower lip and tentacular membrane (Figs 7A–B; 8B–C; 10A & 11C). Segments 1–2 with small lateral lappets; segment 1 with inconspicuous ventral collar; segment 2 with conspicuous ventral collar (Figs 7B; 8C & 11D). Segments 3–7 with lateral lappets, and with a conspicuous dorsal rounded projection on lateral lappets and largest on segment 5; forming thickened ventral membranous collars (ventral lobes) on anterior margins of segments 3–7, lobes those of segment 5 largest; ventral lobes of segment 3 with an inverted “n” shaped invagination in centre, others with uniform smooth margins (Figs 7A–B; 8B–C; 10A & 11C–D). Lateral lappets with conspicuous projection, largest on segment five (Figs 7C; 8B–D; 10B & 11C). Ventral glandular bands and glandular areas around parapodia absent. Branchia as single elongate structure dorsally on segments 2–4, consisting of two pairs of posterior lobes and pair of anterior lobes (Figs 7A; 8B, E; 10C & 11E). BL5–6 fused completely, and distinctly prolonged about 1/2 posterior lobes. Posterior lobes fused for about 1/4 their length. BL1–2 much longer and greater than BL3–4. BL1– 2 and BL5–6 with large lamellae, without distal tip; lamella of BL1–2 and BL5–6 with longitudinal ridges with cilia, without a row of papilla; BL3–4 with small lamellae and distal tip (Figs 8E–G & 10C). Thorax with 20 segments without dorsal hump. Notopodia 18 pairs, present on segments 3–20 (chaetigers 1– 18). First three pairs inserted more dorsally to subsequent ones; first two pairs strongly reduced with shorter and finer chaetae than following ones, notochaetae appearing to arise from body wall (Figs 7A, C; 8B–D; 10A–B & 11C). Chaetae arranged in 2 tiers, lower tier with finely pointed chaetae and upper tier with narrowly–winged chaetae; chaetae of lower tier finer and about 2/3 length of those of upper tier (Fig. 9D–G). Neuropodia beginning from segment 8 (chaetiger 6), and present on all subsequent segments. Thoracic neuropodia as sessile pinnules. First neuropodia with 6 geniculate acicular hooks; geniculate hooks arranged in single row throughout with pointed tips and sharply bent, and showing different degrees of bending depending on size; ventral geniculate hooks smaller and more bent than dorsal ones (Figs 7D; 9A & 10D–E). Subsequent thoracic neuropodia with one row of 8–10 long-handled uncini per torus; uncini with main fang and several rows of secondary teeth, with 2–4 major teeth in first row above main fang (Figs 7E; 9B–C & 10F–G). Abdomen with 30 segments with length gradually decreasing posteriorly. Abdominal neuropodia as foliaceous pinnules with about 36 avicular uncini; arranged in single row (Figs 9H & 10H). Abdominal uncini with strongly crested head, covered with numerous small and scale-like teeth (Figs 7F; 9J–I & 10I). Pygidium blunt without appendages (Figs 10J & 11F). The methyl green staining similar to pattern 5 of Schüller & Hutchings (2010), compact green colour of the first five segments, a likely J-shaped glandular region in segment 5, then becoming striped and gradually fading to weak striped in posterior abdominal segments (Fig. 11A–B). Margin of lower lip without white stripe on peristomium. Thoracic notopodia, abdominal neuropodia and branchial tips and lamellae all lacking any staining. Variability. Complete individuals ranging from 6.9–25.9 mm in length, 1.4–3.0 mm in width of anterior chaetigers excluding the chaetae and 29–32 abdominal segments. Large specimens with greater width and more abdominal segments than smaller ones (Fig. 12A). LRTA ranging from 0.7–1.8, showing large specimens possibly with a smaller LRTA and relatively long abdomen (Fig. 12B). Geniculate hooks ranging from 5–7 in number, with larger specimens tending to have more geniculate hooks. Thoracic neuropodia with 6–10 uncini per torus, number increasing with size of individual which is presumably linked to age. Remarks. Terebellides yangi n. sp. is characterised by a pair of anterior branchial lobes which are distinctly prolonged, lateral lappets of segments 3–7 which have a conspicuous rounded projection (largest on segment 5), neuropodia in segment 8 (chaetiger 6) which have sharply bent geniculate hooks and subsequent thoracic neuropodia which have few (6–10) uncini per torus arranged in a single row. According to published descriptions, there are another 10 species like Terebellides yangi n. sp. with pair of anterior branchial lobes distinctly prolonged, with geniculate acicular chaetae in TC6 only, and without thoracic dorsal hump (Schüller & Hutchings 2013; Parapar & Hutchings 2014). Terebellides yangi n. sp. is distinguished from Terebellides kobei Hessle, 1917 (type locality Japan), Terebellides longicaudatus Hessle, 1917 (type locality Southern Ocean) and Terebellides reishi Williams, 1984 (type locality south-central California) by the arrangement of thoracic neuropodial uncini. Terebellides yangi n. sp. has only a single row of thoracic neuropodial uncini, whereas in the other species thoracic neuropodial uncini are present in double or partial double rows. Terebellides yangi n. sp. and Terebellides woolawa Hutchings & Peart, 2000 (type locality Australia) are different from Terebellides bisetosa Hartmann-Schröder, 1965 (type locality Chile), Terebellides brevis Imajima & Williams, 1985 (type locality Japan), Terebellides gracilis, Malm, 1874 (type locality Norwegian North Sea), Terebellides kerguelensis McIntosh, 1885 (type in Southern Ocean), Terebellides malvinensis Bremec & Elias, 1999 (type locality Argentina), Terebellides narribri Hutchings & Peart, 2000 (type locality Australia) and Terebellides stroemii Sars, 1835 (type locality Norwegian North Sea) by having less well developed notopodia of TC1 and TC2 compared to those of subsequent notopodia. Terebellides yangi n. sp. is easily distinguished from Terebellides woolawa as in the new species, BL1–2 are much longer and wider than BL3–4, posterior lobes fused for about 1/4 their length; neuropodia with sharply bent geniculate acicular hooks in TC6, and few (6–10) uncini per torus in subsequent neuropodia. In contrast in Terebellides woolawa, BL1–2 and BL3–4 are almost equal, posterior branchial lobes fused for about half of their length; neuropodia with weakly bent geniculate acicular hooks in TC6, and more uncini (10–20) per torus in subsequent neuropodia. In addition, species with characters similar to Terebellides yangi n. sp. are recorded from very different geographical regions. Distribution. Known from Beibu Gulf and Daya Bay of the northern South China Sea (Fig.1). Habitat. Found in muddy substrates in shallow water (12.0–35.0 m depths). Etymology. The species is named after Professor Dejian Yang, for his contributions to the taxonomy of Chinese polychaetes.

Based on specimens collected during several sampling programmes mainly in the northern North Sea, Scotland, a new species of the genus Terebellides (Polychaeta; Trichobranchidae) was found and described herein as Terebellides shetlandica spec. nov. The new species is primarily characterised by the presence of a long pointed posterior filament in the ventral branchial lobes. The species is compared with other Terebellides species described or reported from North Atlantic waters, and an updated key to the Terebellides species of the North East Atlantic and Mediterranean Sea is provided. The presence of copepods of the genus Melinnacheres attached to the thorax of this species is reported. Morphology of T. shetlandica spec. nov. was also studied with SEM and micro-CT. Branchial characters used in the taxonomy of the genus are reviewed and four general branchial types are defined.

We investigate mitochondrial (COI, 16S rDNA) and nuclear (ITS2, 28S rDNA) genetic structure of North East Atlantic lineages of Terebellides, a genus of sedentary annelids mainly inhabiting continental shelf and slope sediments. We demonstrate the presence of more than 25 species of which only seven are formally described. Species boundaries are determined with molecular data using a broad range of analytical methods. Many of the new species are common and wide spread, and the majority of the species are found in sympatry with several other species in the complex. Being one of the most regularly encountered annelid taxa in the North East Atlantic, it is more likely to find an undescribed species of Terebellides than a described one. © 2018 Nygren et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Terebellides baliensis sp. nov. Figs 4 A���G, 5A���D, 6A���D Material examined. Holotype (NMNS 7743-4), station D13 (25��11��35˝ N 121��21��34˝E), Bali, New Taipei City, subtidal muddy bottom, 10 January 2010; paratypes (all type information the same as holotype): one specimen (NMNS7743-5), station D7 (25��13��14˝N 121��22��38˝E), 4 October 2008; one specimen (NMNS7743-6), station D9 (25��12��32˝N 121��22��38˝E), 8 April 2009; two specimens (NMNS7743-7), station B4 (25��11��48˝N 121��23��48˝E), 11 January 2010; one specimen (NMNS7743-8), station D6 (25��12��50˝N 121��22��20˝E), 11 January 2010; one specimen (NMNS7743-9), station D1 (25��12��18˝N 121��23��02˝E), 21 April 2011; one specimen (NMNS7743-10), station B3 (25��10��48˝N 121��23��15˝E), 8 August 2011; one specimen (NMNS7743-11), station D8 (25��11��36˝N 121��21��35˝E), 26 March 2012; one specimen (NMNS7743-12), station D8 (25��11��36˝N 121��21��35˝E), 6 January 2013; one specimen (NMNS7743-13), station D8 (25��11��36˝N 121��21��35˝E), 6 January 2013; three specimens (NMNS7743-14), station D8 (25��11��36˝N 121��21��35˝E), 6 January 2013; one specimen (NMNS7743-15), station D7 (25��13��14˝N 121��22��38˝E), 2 January 2014; one specimen (NMNS7743-16), station B1 (25��8��33˝N 121��20��30˝E), 9 January 2015. Description. Holotype, complete, branchiae partially deformed; in fresh paratype (NMNS 7743-10, Fig. 4 A), anterior body mostly bright yellow; preserved holotype mostly beige in alcohol (Fig. 4 B); body length 24.5 mm with 55 segments, maximum width 1.9 mm on segment 10. Prostomium attached to dorsal surface of upper lip, basal part without eyespots; buccal tentacles of two forms, mostly simple with tapering tips, regardless of tentacle length, and others tentacles long with expanding tips (Fig. 4 C���D); peristomium forming lips, continuing dorsally; upper lip compact, low ridge; lower lip large, triangular (Fig. 4 C���D). Segment 1 conspicuous dorsally, eversible proboscis protruded, cone-shaped (Fig. 4 A���E); segment 2 to 12 with various degrees of thickened on lateral and ventral body, forming short lobes, collar-like, across ventrum covering posterior portion of preceeding segments; hump-like thickening of ventrum more marked on segment 3 to 7 (Fig. 4 C, E). Branchiae formed by single mid-dorsal stem arising between segment 2 to 4 and four-lobed (two large and two small) lamellate branchiae (Fig. 4 F); large lamellae mostly fused basally, small partly fused basally. Notopodia as 18 pairs, on segment 3 to 20; first pair of notopodia less developed than subsequent ones (Fig. 4 C, E), second to six pairs with short notopodia, thereafter progressively longer to maximum length on segment 13, similar length on remaining notopodia (Fig. 4 B���C). First pair of notopodia with few notochaetae (Fig. 4 C, E); notopodia on segment 4 to 20 with two rows of narrowly-winged notochaetae (Fig. 4 G). Neuropodia present from segment 8 to last segment prior to pygidium (48 pairs); neurochaetae emerging from body wall; first thoracic pair bearing geniculate hooks, about 4���7 on each side, moderate to strongly bent, with pointed tip (Fig. 5 A); subsequent thoracic neuropodia with long-handled acicular uncini (Fig. 5 B), with 5���6 rows of secondary teeth (Fig. 5 C���D); abdominal neuropodia present from segment 21, ginkgo leaf-like, bearing single row of avicular uncini on neuropodia margin, uncini short-handled with about 4 rows of secondary teeth (Fig. 5 E��� F). Genital and nephridial papillae not observed. Pygidium round (Fig. 4 B). Variations: based on complete specimens (NMNS 7743-6; 31 mm in length; NMNS 7743-15, 22 mm in length). First neuropodia bearing 6���6/7���9 geniculate hooks on right and left side, respectively; tip of geniculate hooks with various degrees of bending; abdomen with 38 and 33+ segments. Etymology. The name is derived from the name of nearby township south to the Tensui River mouth where the worm was collected. Type locality. Offshore from Bali, New Taipei City, Taiwan. Distribution. Known only from the type locality. Remarks. Of currently known Terebellides, five species were described from the East Asia and one species from the Southeast Asia. They are: Terebellides brevis Imajima & Williams, 1985 (Japan), Terebellides horikoshii Imajima & Williams, 1985 (Japan), Terebellides intoshi Caullery, 1915 (Indonesia), Terebellides japonica Moore, 1903 (Japan), Terebellides kobei Hessle, 1917 (Japan), and Terebellides lineata Imajima & Williams, 1985 (Japan) (Sch��ller & Hutching 2013). Disregarding the presence of eversible proboscis in T. baliensis sp. nov., only T. brevis, T. japonica and T. lineata of these six species are remotely similar to the former species by having the first thoracic chaetiger distinctively less developed than subsequent ones (Imajima & Williams 1985). Moreover, T. brevis has mucronate tips on geniculate hooks and 20���25 abdominal segments (Imajima & Williams 1985: 12���13, fig. 3e), whereas T. baliensis sp. nov. has no mucronate tips on geniculate hooks (Fig. 5 A) and 35 abdominal segments. Terebellides japonica has pointed sheath covering blunt tipped geniculate hooks and an exceptionally long abdomen, with almost 2/3 the length of the animal (45���50 abdominal segments) (Imajima & Williams 1985). In contrast, T. baliensis sp. nov. has pointed tips and without sheath covering geniculate hooks and 35 abdominal segments. Terebellides lineata can be distinguished from T. baliensis sp. nov. by having four free and subequal sized branchial lobes (Imajima & Williams 1985), comparing to the presence of two large and two small basally fused branchial lobes in the latter species., Published as part of Hsueh, Pan-Wen & Li, Kuo-Rong, 2017, Additions of new species to Thelepus (Thelepodidae), with description of a new Terebellides (Trichobranchidae) from Taiwan, pp. 429-439 in Zootaxa 4244 (3) on pages 435-438, DOI: 10.11646/zootaxa.4244.3.10, http://zenodo.org/record/432117, {"references":["Imajima, M. & Williams, S. J. (1985) Trichobranchidae (Polychaeta) chiefly from the Sagami and Suruga Bays, collected by the R / V Tansei-Maru (cruises KT- 65 ~ 76). Bulletin of the National Science Museum, Tokyo, Series A (Zoology), 11 (1), 7 - 18.","Schuller, M. & Hutchings, P. A. (2013) New species of Terebellides (Polychaeta: Trichobranchidae) from the deep Southern Ocean, with a key to all described species. Zootaxa, 3619 (1), 1 - 45."]}

Following a recent report on two new species of Thelepus for the Taiwan, we describe two more new species, T. hemeiensis sp. nov. and T. wuchiensis sp. nov., for the genus. In addition, a new species of the Family Trichobranchidae is also described, Terebellides baliensis sp. nov., which was collected from an offshore monitoring survey in northwestern Taiwan. The genus Terebellides as well as the Family Trichobranchidae are reported for the first time from Taiwanese waters.

Genus Terebellides Sars, 1935 Type species. Terebellides stroemii Sars, 1835 Remarks. Members of Terebellides are characterised by having fused branchial stems and multi-lobed branchiae with transverse lamellae on mid-dorsum, 18 thoracic chaetigers, first neuropodia with geniculate hooks and subsequent ones with denticulate hooks (Hutchings & Peart 2000; Sch��ller & Hutchings 2013; Hutchings et al. 2015). Hutchings & Peart (2000) emended the generic diagnosis given in Holthe (1986) by including the presence of ornamented notochaetae and the variation in the number of branchial lobes and their relative development. Sch��ller & Hutchings (2013) added a morphologic feature to the generic diagnosis, the presence of two segments with geniculate hooks, which is found in Terebellides crux Sch��ller & Hutchings, 2013. In the present study, all specimens examined showed various degree of proboscis protrusion. Yet, this observation might raise a question on whether having protruded proboscis of the present species is a stable morphological character. We are not firmly sure about the stability of this morphological character. Therefore, we tend to agree with Hutching & Peart (2000), who stated ��� The retractile nature of the proboscis has not previously been recorded and as this is used as a defining character for the genus, a specimen with a fully retractable proboscis could be difficult to identify ���, and make no attempt to include the presence of eversible proboscis in generic diagnosis for Terebellides in the present study. To date, the genus has 55 valid species, including five recently describes species: Terebellides akares Hutchings, Nogueira & Carrerette, 2015, Terebellides mediterranea Parapar, Mikac & Fiege, 2013, Terebellides hutchingsae Parapar, Moreira & Martin, 2016, Terebellides persiae Parapar, Moreira, Gil & Martin, 2016, and Terebellides shetlandica Parapar, Moreira & O'Reilly, 2016 (Sch��ller & Hutchings 2013, Hutchings et al. 2015 & Parapar et al. 2016a, b, c). The present study adds one more species to the genus., Published as part of Hsueh, Pan-Wen & Li, Kuo-Rong, 2017, Additions of new species to Thelepus (Thelepodidae), with description of a new Terebellides (Trichobranchidae) from Taiwan, pp. 429-439 in Zootaxa 4244 (3) on pages 433-435, DOI: 10.11646/zootaxa.4244.3.10, http://zenodo.org/record/432117, {"references":["Sars, M. (1835) Beskrivelser og Iagttagelser over nogle moerkelige eller nye i Havet ved den Bergenske Kyst levende Dyr af Polypernes, Acalephernes, Radiaternes, Annelidernes og Molluskernes classer, med en kort Oversigt over de hidtil af Forfatteren sammesteds fundne Arter og deres Forekommen. Thorstein Hallagers Forlag hos Chr. Dahl, R. S., Bergen, xii + 81 pp., 15 pls.","Hutchings, P. & Peart, R. (2000) A revision of the Australian Trichobranchidae (Polychaeta). Invertebrate Taxonomy, 14, 225 - 272.","Schuller, M. & Hutchings, P. A. (2013) New species of Terebellides (Polychaeta: Trichobranchidae) from the deep Southern Ocean, with a key to all described species. Zootaxa, 3619 (1), 1 - 45.","Hutchings, P., Nogueira, J. M. de M. & Carrerette, O. (2015) Telothelepodidae, Thelepodidae and Trichobranchidae (Annelida, Terebelliformia) from Lizard Island, Great Barrier Reef, Australia. Zootaxa, 4019 (1), 240 - 274. https: // doi. org / 10.11646 / zootaxa. 4019.1.12","Holthe, T. (1986) Evolution, systematics, and distribution of the Polychaeta Terebellomorpha, with a catalogue of the taxa and a bibliography. Gunneria, 55, 1 - 236.","Parapar, J., Mikac, B. & Fiege, D. (2013) Diversity of the genus Terebellides (Polychaeta: Trichobranchidae) in the Adriatic Sea with the description of a new species. Zootaxa, 3691 (3), 333 - 350.","Parapar, J., Moreira, J., Gil, J. & Martin, D. (2016 c) A new species of the genus Terebellides (Polychaeta, Trichobranchidae) from the Iranian coast. Zootaxa, 4117 (3), 321 - 340.","Parapar, J., Moreira, J & O'Reilly, M. (2016 b) A new species of Terebellides (Polychaeta: Trichobranchidae) from Scottish waters with an insight into branchial morphology. Marine Biodiversity, 46 (1), 211 - 225.","Parapar, J., Moreira, J. & Martin, D. (2016 a) On the diversity of the SE Indo-Pacific species of Terebellides (Annelida; Trichobranchidae), with the description of a new species. PeerJ, 4, e 2313."]}

The genus Terebellides is, despite its often low abundances, a common and diverse element of benthic soft sediment communities at all depths. In recent years, careful examination of specimens has resulted in numerous descriptions of new species of Terebellides increasing the number of species in the genus to over forty. For the Southern Ocean currently only two species are considered valid, both recorded for shelf and slope depths. Here, we present findings of eleven new Antarctic species originating from depths between 480 m and 4720 m. Six of these are formally described ( T. canopus sp. n., T. crux sp.n., T. mira sp.n., T. rigel sp.n., T. sirius sp.n., and T. toliman , sp.n.). One species, T. crux sp.n., bears two segments with geniculate hooks, a trait already known for the genus but conflicting with the original generic diagnosis. To include this trait the generic diagnosis of Terebellides is amended. An identification key for all species of Terebellides is given, as well as a maximum parsimony phylogeny of the genus based on morphological characters.

Traballo fin de grao (UDC.CIE). Bioloxía. Curso 2016/2017 [Resumen] El Microscopio Electrónico de Barrido (MEB) es uno de los instrumentos más versátiles para el examen y análisis de características micro estructurales cuya utilidad radica en su alta resolución y su profundidad de campo, permitiendo la obtención de imágenes estereoscópicas de muy alta definición. Este TFG explora el uso del MEB como herramienta en el estudio taxonómico de los animales, y en particular de los Anélidos Poliquetos. Para ello se emplearán las imágenes obtenidas a partir del estudio de varios ejemplares del género Terebellides (Annelida; Trichobranchidae) pertenecientes a tres especies procedentes de tres enclaves geográficos diferentes en la costa oriental del Océano Atlántico: T. shetlandica Parapar, Moreira & O’Reilly, 2016 de las Islas Shetland (N Escocia), y dos ejemplares de dos especies todavía no descritas y procedentes de Galicia (NW España) y Congo respectivamente. El estudio se ha centrado en la forma de las sedas y branquias, con el objeto de valorar la posibilidad de que sean o no la misma especie. [Resumo] O Microscopio Electrónico de Varrido (MEV) é un dos instrumentos máis versátiles para o examen e análise de características micro estructurais cuxa utilidade radica na súa alta resolución e profundidade de campo, permitindo a obtención de imaxes estereoscópicas de moi alta definición. Este TFG explora o uso do MEB como ferramenta no estudio taxonómico dos animais, e en particular dos Anélidos Poliquetos. Para elo se empregarán as imaxes obtidas a partires do estudo de varios exemplares do xénero Terebellides (Annelida; Trichobranchidae) pertencentes a tres especies procedentes de tres enclaves xeográficos diferentes da costa oriental do Océano Atlántico: T. shetlandica Parapar, Moreira & O’Reilly, 2016 das Illas Shetland (N Escocia), e dous exemplares de dous especies todavía non descritase procedentes de Galicia (NW España) e Congo respectivamente. O estudio centrouse na forma das sedas e branquias, co oxecto de valorar a posibilidade de que sexan ou non a mesma especie. [Abstract] The Scanning Electron Microscope (SEM) is one of the most versatile instruments for the examination and analysis of micro structural characteristics, and whose utility lies in its high resolution and depth of field, allowing obtaining stereoscopic very high definition images. This TFG explores the use of MEB as a tool in the animal taxonomic study, and in particular of the Polychaetes. Shape of chaetae and branchiae has been studied in three Tricobranchid polychaete specimens of genus Terebellides, one belonging to an already described species, T. shetlandica Parapar, Moreira & O’Reilly, 2016 from the Shetland Islands (N Scotland), and two specimens from two still undescribed species, one from the Galician coasts (NW Spain) and one from the Congo coast respectively, in order to explore the possibility of being or not the same species.

The study of material collected during routine monitoring surveys dealing with oil extraction and aquaculture in waters off Myanmar (North Andaman Sea) and in the Gulf of Thailand, respectively, allowed us to analyse the taxonomy and diversity of the polychaete genus Terebellides (Annelida). Three species were found, namely Terebellides cf. woolawa, Terebellides hutchingsae spec. nov. (a new species fully described and illustrated), and Terebellides sp. (likely a new species, but with only one available specimen). The new species is characterised by the combination of some branchial (number, fusion and relative length of lobes and papillation of lamellae), and thoracic (lateral lobes and relative length of notopodia) characters and is compared with all species described or reported in the SW Indo-Pacific area, as well as with those sharing similar morphological characteristics all around the world. The taxonomic relevance of the relative length of branchial lobes and different types of ciliature in branchial lamellae for species discrimination in the genus is discussed. A key to all Terebellides species described in SE Indo-Pacific waters is presented. Ministerio de Economía y Competitividad; CGL2014-53332-C5-3-P Ministerio de Economía y Competitividad; TM2013-43287-P Cataluña. Generalitat; 2014SGR120

28 páginas, 8 figuras, 2 tablas., The study of material collected during routine monitoring surveys dealing with oil extraction and aquaculture in waters off Myanmar (North Andaman Sea) and in the Gulf of Thailand, respectively, allowed us to analyse the taxonomy and diversity of the polychaete genus Terebellides (Annelida). Three species were found, namely Terebellides cf. woolawa, Terebellides hutchingsae spec. nov. (a new species fully described and illustrated), and Terebellides sp. (likely a new species, but with only one available specimen). The new species is characterised by the combination of some branchial (number, fusion and relative length of lobes and papillation of lamellae), and thoracic (lateral lobes and relative length of notopodia) characters and is compared with all species described or reported in the SW Indo-Pacific area, as well as with those sharing similar morphological characteristics all around the world. The taxonomic relevance of the relative length of branchial lobes and different types of ciliature in branchial lamellae for species discrimination in the genus is discussed. A key to all Terebellides species described in SE Indo-Pacific waters is presented., The study has been financed by the research projects ``Fauna Ibérica: Polychaeta VI: Palpata, Canalipalpata I'' (CGL2014-53332-C5-3-P) and ``MarSymBiomics'' (CTM2013-43287-P), funded by the Ministerio de Economía y Competitividad of Spain, as well as by the Consolidated Research Group on Marine Benthic Ecology (2014SGR120), funded by the Generalitat de Catalunya, and the research contract between the CEAB (CSIC) and the French company Créocéan.

Foram estudados os Polychaeta coletados durante três Expedições Oceanografcias brasilaeiras a Antarticia (Dezembro - 1996 a Janeiro - 1997; Dezembro - 1997 a Janeiro - 1998; Janeiro a Abril - 2001) para a Baia do Almirantado. Um total de 127 espécimes foi examinado e 18 espécies, pertencentes a 12 famílias, foram identificados. A família Terebellidae foi a que apresentou o maior número de espécies, e Terebellidae, Nephtyidae e Polynoidae apresentaram os maiores número de indivíduos coletados. As espécies Terebellides longicaudatus e Aglaophamus trissophyllus foram reportadas pela primeira vez na Baía e os gêneros Proclea (Terebellidae), Neanthes (Nereididae), Bradabyssa (Flabelligeridae), Euclymene (Maldanidae), foram reportados pela primeira vez na enseada de Martel. The Polychaeta collected during three distinct Brazilian Antarctic Expeditions (December 1996 to January-1997; December 1997 to January 1998; January to April 2001) in the Admiralty Bay have been studied. A total of 127 specimens have been examined and 18 species, belonging to 12 families, have been identified. The family Terebellidae was the most important family in number of species, and Terebellidae, Nephtyidae and Polynoidae in number of individuals. The species Terebellides longicaudatus and Aglaophamus trissophyllus were reported from the first time to the Bay and the genera Proclea (Terebellidae), Neanthes (Nereididae), Bradabyssa (Flabelligeridae), Euclymene (Maldanidae) were reported from the first time in the Martel Inlet.

Unobranchus abyssalis Hartman, 1965, is redescribed. The genus Unobranchus is synonymised with Terebellides. The genera of Trichobranchidae and possible evolutionary pathways within the family are discussed. Some comments are also given on the relationships of Trichobranchidae and other families of the order Terebellida. Keys are given to the genera of Trichobranchidae and the subfamilies of Terebellidae sensu lato.

A new polychaete species of the family Terebellidae, Terebellides irinae sp. n., has been described from materials collected in the Canadian Basin by the international Hidden Ocean 2005 expedition on board the US Coast Guard icebreaker (WAGB-20) Healy. The new species differs from other closely related species by its underdeveloped ventral branchial lobes that are at least two times shorter than the dorsal ones, sometimes reduced to barely noticeable cones and in that the aciculum-like neurochaetes of the 6th setigerous segment are curved at a right angle and have a thin capillaceous tip. Specimens of this polychaete worm are small, no more than 15 mm long.

Genus Terebellides Sars, 1835, emended Terebellides. ��� Hutchings & Peart 2000: 238 ���239; Muir 2011: 144. Type-species. Terebellides stroemii Sars, 1835, by monotypy. Diagnosis. Transverse prostomium attached to dorsal surface of upper lip; basal part without eyespots; distal part extending along dorsal margin of upper lip until near anterior margin. Buccal tentacles usually of two types, uniformly cylindrical and expanded at tips. Peristomium forming lips, continuing dorsally as narrow annulation; relatively large upper lip, circular and slightly convoluted; lower lip expanded, forming scoop-like process. Short anterior segments, segment 1 visible ventrally, posterior to lower lip, sometimes also conspicuous dorsally; following anterior segments with lobes as low ventral collars. Single 1���5 lobed lamellate branchia inserted by thick branchial stem between segments 2���3 or 2���4. Anterior body poorly glandular ventrally, smooth. Notopodia beginning from segments 3 or 4, terminating on segment 20; if beginning from segment 3, first pair shorter than following ones; short, conical notopodia, not bilobed. Narrowly-winged notochaetae in both rows, wings inconspicuous under light microscopy, visible as short and fine hairs under SEM. Neuropodia beginning from segments 7 or 8, uncini emerging directly from body wall. Neurochaetae of first 1���2 segments as thin, distally tapered acicular spines, following neuropodia with acicular uncini until end of notopodia; abdominal neuropodia as foliaceous pinnules, bearing avicular uncini. Nephridial papillae only on segment 3, genital papillae, if present, on segments 6���7, at bases of notopodia, posterior and dorsal. Pygidium smooth to slightly crenulate. Remarks. Terebellides is a well known genus, characterized by the highly unusual branchia. The type species, T. stroemii Sars, 1835, has been reported worldwide and is clearly a case of a complex of sibling species. In a recent redescription of T. stroemii, Parapar & Hutchings (2014) designated a neotype, redefined this species and suggested it is restricted to Northern Atlantic waters. Work in progress utilising both molecular and morphological tools is revealing many other species currently undescribed in this region of the North Atlantic (Parapar, Hutchings & others, in prep.), all closely resembling T. stroemii morphologically, but differing genetically. Hutchings & Peart (2000) reviewed this genus in Australia and described four new species, but we suspect additional species occur. This is confirmed by the present study, in which we describe a new species from Lizard Island., Published as part of Hutchings, Pat, Nogueira, Jo��o Miguel Matos & Carrerette, Orlemir, 2015, Telothelepodidae, Thelepodidae and Trichobranchidae (Annelida, Terebelliformia) from Lizard Island, Great Barrier Reef, Australia, pp. 240-274 in Zootaxa 4019 (1) on pages 258-261, DOI: 10.11646/zootaxa.4019.1.12, http://zenodo.org/record/253393, {"references":["Sars, M. (1835) Beskrivelser og Iagttagelser over nogle maerkelige eller nye i Havet ved den Bergenske Kyst Levende Dyr af Polypernes, Acalephernes, Radiaternes, Annelidernes og Molluskernes classer, med en kort Oversigt over de hidtil af Forfatteren sammesteds fundne Arter og deres Forekommen. T. Hallager, Bergen, 81 pp.","Hutchings, P. A. & Peart, R. (2000) A revision of the Australian Trichobranchidae (Polychaeta). Invertebrate Taxonomy, 14 (2), 225 - 272. http: // dx. doi. org / 10.1071 / IT 98005","Muir, A. I. (2011) A redescription of Unobranchus (Annelida: Terebellidae: Trichobranchidae), with notes on the systematics of Trichobranchidae. Italian Journal of Zoology, 78 (S 1), 140 - 147. http: // dx. doi. org / 10.1080 / 11250003.2011.583490","Parapar, J. and Hutchings, P. (2014). Redescription of Terebellides stroemii (Polychaeta, Trichobranchidae) and designation of a neotype. Journal of the Marine Biological Association of the United Kingdom, 96 (2), 323 - 337."]}

Genus Terebellides M. Sars, 1835 Terebellides gracilis (Malm, 1874) DISTRIBUTION: NA. LITERATURE RECORDS: Parapar et al. 2013. NEW RECORDS: BM 52, BM 53. * Terebellides mediterranea Parapar, Mikac & Fiege, 2013 DISTRIBUTION: NA. LITERATURE RECORDS: Parapar et al. 2013. NEW RECORDS: BM 52. Terebellides stroemii M. Sars, 1835 DISTRIBUTION: NA, CA, SA. LITERATURE RECORDS: Grube 1864; Stossich 1883; Carus 1884; Brusina 1896; Graeffe 1905; Leidenfrost 1908; Vatova 1928, 1931a; Fauvel 1934; Vatova 1934, 1935; Fauvel 1940; Vatova 1942, 1943, 1949 a; Me��trov 1957; Banse 1959; Kiseleva 1964; Scaccini 1967; Gamulin-Brida et al. 1968; Bellan 1969; Orel & Mennea 1969; Banse 1970; Zavodnik 1971; Marcuzzi 1972; Katzmann 1972, 1973a, 1973 b, 1973 f; Avčin et al. 1974; Gamulin-Brida 1974; Matja��ić & ��tirn 1975; Amoureux 1976; Bellan 1976; Cognetti-Varriale & Zunarelli-Vandini 1978; Zavodnik et al. 1978; Amoureux 1979; Zavodnik 1979; Zavodnik et al. 1981; Amoureux 1983 a, 1983 c; Avčin & Vri��er 1983; Fassari 1983; Katzmann 1983; Požar-Domac 1983; Del Piero et al. 1984; Stjepčević et al. 1984; Zavodnik et al. 1985; Gillet 1986; Zavodnik & Vidaković 1987; Aleffi et al. 1988; Županović & Jardas 1989; Požar-Domac 1994; Zahtila 1995, 1997; Zavodnik & Kovačić 2000; Crema et al. 2001; Cantone & Di Pietro 2002; Ceschia et al. 2002; Aleffi et al. 2003; Solis-Weiss et al. 2004; Boscolo et al. 2006; Zavodnik et al. 2006; Simonini et al. 2007; Solis-Weiss et al. 2007; Castelli et al. 2008; Mikac et al. 2011; Musco et al. 2011; Parapar et al. 2013. NEW RECORDS: BM 11, BM 12, BM 13, BM 17, BM 20, BM 21, BM 22, BM 26, BM 27, BM 28, BM 38, BM 39, BM 40, BM 42, BM 43, BM 52, BM 53, BM 54, BM 61, BM 63, BM 64, BM 65, BM 66, BM 91. REMARKS: Until recently the only species of Terebellides reported for the Mediterranean Sea was T. stroemii. However, recent research in the NA (Parapar et al. 2013) revealed two more species to be present, T. gracilis (Malm, 1874) and a newly described species T. mediterranea Parapar, Mikac & Fiege, 2013. All former records of T. stroemii in the Adriatic need to be reviewed as some of them may belong to other species of Terebellides. Parapar & Hutchings (2014) described a neotype of T. stroemii from Norway; they performed a comparative study of the morphological characteristics of T. stroemii from several recent descriptions in the north-east Atlantic (including the one from the Adriatic Sea by Parapar et al. 2013) and observed slight differences among them, suggesting that several cryptic species are present. These species are difficult to be identified using only a traditional morphological study of external characters, thus molecular methodologies will have to be performed., Published as part of Mikac, Barbara, 2015, A sea of worms: polychaete checklist of the Adriatic Sea, pp. 1-172 in Zootaxa 3943 (1) on pages 146-147, DOI: 10.11646/zootaxa.3943.1.1, http://zenodo.org/record/244663, {"references":["Parapar, J., Mikac, B. & Fiege, D. (2013) Diversity of the genus Terebellides (Polychaeta: Trichobranchidae) in the Adriatic Sea with the description of a new species. Zootaxa, 3691 (3), 333 - 350. http: // dx. doi. org / 10.11646 / zootaxa. 3691.3.3","Grube, E. (1864) Die Insel Lussin und ihre Meeresfauna. Verlag Ferdinand Hirt, Breslau, 113 pp.","Stossich, M. (1883) Prospeto della fauna del Mare Adriatico. IV Vermes. Bollettino della Societa adriatica di scienze naturali in Trieste, 7, 168 - 242.","Carus, J. V. (1884) Prodromus Faunae Mediterraneae, I. E. Schweizerbarfsche Verlagshandlung (E. Koch), Stuttgart, 524 pp.","Brusina, S. (1896) Faunisticki prilozi sa putovanja yachte \" Margite \" po Jadranskom moru. Glasnik Hrvatskog naravoslovnog Drustva, 9 (1 - 6), 261 - 297.","Graeffe, E. (1905) Ubersicht der Fauna des Golfes von Triest. X. Vermes. I. Teil. Arbeiten aus den zoologischen Institute der Universitat Wien und der zoologischen Station in Trieste, 15, 317 - 332.","Leidenfrost, G. (1908) Adatok a Quarnero zoogeographiajahoz. Allatani Kozlemenyek, 7 (2), 95 - 115.","Vatova, A. (1928) Compendio della Flora e Fauna del Mare Adriatico presso Rovigno. Bollettino. R. Comitato Talassografico Italiano, 143, 1 - 614.","Vatova, A. (1931 a) La fauna bentonica del Canal di Leme in Istria. Bollettino. R. Comitato Talassografico Italiano, 181, 1 - 10.","Fauvel, P. (1934) Annelides Polychetes de Rovigno d'Istria. Thalassia, 1 (7), 1 - 78.","Vatova, A. (1934) Ricerche quantitative sul bentos del golfo di Rovigno. Note del Istituto Italo-Germanico di biologia marina di Rovigno d`Istria, 12, 1 - 12.","Vatova, A. (1935) Ricerche preliminari sulle biocenosi del Golfo di Rovigno. Thalassia, 2 (2), 1 - 30.","Fauvel, P. (1940) Annelides Polychetes de la Haute Adriatique. Thalassia, 4 (1), 1 - 24.","Vatova, A. (1942) La fauna bentonica del Carnaro e del Canal d'Arsa. Note del Istituto Italo-Germanico di biologia marina di Rovigno d`Istria, 2 (23), 1 - 19.","Vatova, A. (1943) Le zoocenosi dell'Alto Adriatico presso Rovigno e loro variazioni nello spazio e nel tempo. Thalassia, 5 (6), 1 - 61.","Vatova, A. (1949 a) La fauna bentonica dell'Alto e Medio Adriatico. Nova Thalassia, 1 (3), 1 - 110.","Mestrov, M. (1957) Kratki prilog poznavanju faune bentoskih polycheta uz obalu otoka Murtera. Bioloski Glasnik, 10, 221 - 226.","Banse, K. (1959) Polychaeten aus Rovinj. Zoologischer Anzeiger, 169, 295 - 313.","Kiseleva, M. I. (1964) Nekotorye dannye o bentose Adriaticeskoga morja. Trudy Sevastopol'skoi Biologicheskoi Stantzii, 17, 28 - 38.","Scaccini, A. (1967) Dati preliminari sulle zoocenosi bentoniche e sulla biomasa in una zona dell'alto e medio Adriatico. Note del Laboratorio di Biologia Marina e Pesca Fano, 2 (3), 25 - 56.","Gamulin-Brida, H., Pozar, A. & Zavodnik, D. (1968) Contributions aux recherches sur la bionomie benthique des fonds meubles de l'Adriatique du nord (II). Bioloski Glasnik, 21, 157 - 201.","Bellan, G. (1969) Contribution a l'etude des Annelides Polychetes de la region de Rovinj (Yougoslavie). Rad Jugoslavenske akademija znanosti i umjetnosti, 354 (13), 25 - 55.","Orel, B., Mennea, B. (1969) I popolamenti bentonici di alcuni tipi di fondo mobile del Golfo di Trieste. Pubblicazioni della stazione zoologica di Napoli, 37 (2), 261 - 276.","Banse, K. (1970) Polychaeta. In: Riedl, R. (Ed.), Flora und Fauna der Adria. Paul Parey, Hamburg und Berlin, pp. 225 - 256.","Zavodnik, D. (1971) Contribution to the dynamics of benthic communities in the region of Rovinj (Nothern Adriatic). Thalassia Jugoslavica, 7, 447 - 514.","Marcuzzi, G. (1972) Le collezioni dell'ex Istituto di Biologia marina di Rovigno conservate presso la stazione Idrobiologica di Chioggia. Atti e Memorie dell'Accademia Patavina di Scienze Lettere ed Arti, 84 (2), 169 - 219.","Katzmann, W. (1972) Die Polychaeten Rovinjs (Istrien / Jugoslawien). Zoologischer Anzeiger, 188, 116 - 144.","Katzmann, W. 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(1976) Inventaire d'une petit collection d'Annelides Polychetes des parages sud de Rovinj (Haute - Adriatique). Thalassia Jugoslavica, 12, 381 - 390.","Bellan, G. (1976) Contribution a l'etude des Annelides Polychetes de quelques fonds meubles circalittoraux des cotes Yougoslaves. Thalassia Jugoslavica, 12, 391 - 397.","Cognetti-Varriale, A. M. & Zunarelli-Vandini, R. (1978) Distribution des Polychetes sur les fonds meubles infralittoraux du Molise (Adriatique). Cahiers de Biologie Marine, 19, 37 - 45.","Zavodnik, D., Span, A., Zavodnik, N., Simunovic, A. & Antolic, B. (1981) Benthos of the western coast of the island Krk (Rijeka Bay, the North Adriatic Sea). Thalassia Jugoslavica, 17, 285 - 337.","Amoureux, L. (1983 a) Annelides Polychetes recueillies par D. Zavodnik. Thalassia Jugoslavica, 19, 1 - 6.","Amoureux, L. (1983 c) Annelides Polychetes de l'Adriatique. Thalassia Jugoslavica, 19, 15 - 21.","Avcin, A. & Vriser, B. (1983) Znacilnosti zdruzb sedimentnega dna obalnega morja Slovenske Istre na primeru Piranskega zaliva. Bioloski Vestnik, 31 (1), 129 - 160.","Fassari, G. (1983) Policheti e molluschi delle Bocche del Cattaro (Jugoslavia). Animalia, 10 (1 / 3), 41 - 46.","Katzmann, W. (1983) Bemerkungen zur Systematik, Okologie und Tiergeographie der mitteladriatischen Weichbodenpolychaeten. Annalen des Naturhistorichen Museums in Wien, 84 / B, 87 - 122.","Pozar-Domac, A. (1983) Polychaeta u bentoskim biocenozama juznog Jadrana. Studia Marina, 13 - 14, 292 - 311.","Del Piero, D., Giorgi, R., Hammerle, A., Orel, G. & Vio, E. (1984) Applicazione di metodi classificazione e ordinamento a dati relativi a campioni del bentos raccolti lungo una radiale della costiera triestina. Nova Thalassia, 6 (Supplement), 625 - 635.","Stjepcevic, J., Parenzan, P., Mandic, S., Stjepcevic, B. (1984) Kvalitativno - kvantitativna istrazivanja polychaeta unutrasnjeg dijela Bokokotorskog zaliva. 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Journal of the Marine Biological Association of the United Kingdom, 2014, 1 - 15. [published online] http: // dx. doi. org / 10.1017 / S 0025315414000903"]}

Terebellides akares n. sp. (Figs 1 G���H, 12���16) Type material. Holotype: NTM W. 023143, Lizard Island, S end of Coconut Beach, reef flat, 14 �� 41 ' 42.120 "S, 145 �� 28 ' 11.280 "E, coll. C. Glasby, 5 Apr 2008, CReefs, complete, 7 mm long, 1 mm wide, with 45 segments. Paratypes: NTM W.025894 (2, 1 mounted on SEM pin), both complete, 10 mm long, 1.5 mm wide, 45 segments, gravid; 5 mm long, 1.0 mm wide, 37 segments; AM W. 45831, MI QLD 2441 (1 mounted on 2 SEM pins); AM W. 47596, CReefs, intertidal, mounted on SEM pin. Other material examined. AM W. 47624, MI QLD 2205, South of Mermaid Cove, 14 �� 38 ' 53 "S, 145 �� 27 'E, coarse coral rubble, 14.5 m, 1 Sep 2010, CReefs, LI��� 10 ���047, complete, small, 34 segments; AM W. 47625, Lizard Island, MacGillivray Reef, 14 �� 38 ' 51 "S, 145 �� 29 ' 16 "E, coral rubble, 7���16 m, 3 Sep 2010, CReefs, LI��� 10 ���062, complete, 40���41 segments, 7 mm long, ~ 1.5 mm maximum width (segs 11���12); AM W. 47626, MI QLD 2244, High Rock, 14 �� 49 ' 34 "S, 145 �� 33 '08"E, coral rubble, 20 m, 11 Sep 2010, CReefs, LI��� 10���134, very small specimen, in poor state of preservation, with ~ 40 segments; AM W. 44168, MI QLD 2359; AM W. 44573, MI QLD 2406. Description. In life with reddish body and dark red branchiae, with well developed vascular system, buccal tentacles colourless (Fig. 1 G���H). Transverse prostomium attached to dorsal surface of upper lip; basal part without eyespots; distal part extending along dorsal margin of upper lip until near anterior margin. Buccal tentacles of two types, short tentacles uniformly cylindrical, slightly expanded at tips, long tentacles more expanded at tips, foliaceous (Figs 12 A���M; 14 A���G, K; 15 A���B; 16 A���E, H). Peristomium forming lips, continuing dorsally as narrow annulation; upper lip large, longer than wide, convoluted; lower lip developed, projecting forwards, with laterally rounded nearly straight distally marginal lobe (Figs 12 B���G, I���M; 14 K; 15 A���B; 16 B���C, E). Anterior segments, until segment 10, with thickened anterior margins lateral and ventrally, forming low lobes as short collars across ventrum covering posterior part of preceeding segment, lobes progressively shorter from segment 3; segment 1 short, conspicuous dorsally, much shorter than following segments, more developed laterally and ventrally, below expanded lower lip, with almost inconspicuous ventral collar; segment 2 dorsally thin, with main stem of branchiae, more developed laterally and ventrally; segment 3 dorsally fused to segment 2, more developed ventrally, as protruding crest, at an angle with anterior segments; following segments aligned with segment 4 (Figs 1 G���H; 12 A���M; 12 A���M; 14 A���B, K���L; 15 A���B; 16 B���C, E). Single 5 -lobed lamellate branchia, lamellae on both sides with several rows of cilia and distal row of scattered papillae ciliated at tips; posterior pair of lobes much shorter, completely free (Figs 1 H; 12 A���M; 14 A, C���D, G���J; 15 A���B; 16 A���B, D, F, H���J). Notopodia beginning from segment 3, first two pairs shorter than following ones, especially first one (Figs 12 A���M; 14 A���D, G, K���L; 15 A���B, D���E, H���I; 16 A���E); narrowly-winged notochaetae in both rows, wings barely visible under light microscopy, visible as short and fine hairs under SEM, those of chaetae of posterior row only present on distal half of chaetae; chaetae of anterior row about 2 / 3 length of those of posterior row (Figs 13 A���D; 15 D���I). Neuropodia beginning from segment 7, sessile, chaetae emerging directly from body wall. Neurochaetae of first 1���2 segments as thin, distally tapered acicular spines subdistally bent at right angle, those of first pair (segment 7) shorter and with bayonet-like tip (Figs 13 E���F; 15 H���I, L); following neuropodia with acicular uncini with 4 rows of secondary teeth until end of notopodia; abdominal neuropodia as foliaceous pinnules, bearing avicular uncini with 3���4 rows of secondary teeth; relatively few uncini per torus throughout (Figs 13 G���M; 14 A���B, K���L; 15 A���C, H���N; 16 B, G). Remarkably short abdomen, with compact segments, about 1 / 3 ��� 1 / 4 of extension of region with notopodia (Figs 12 A���D, N���O; 14 A���B; 15 C). Nephridial papillae on segment 3, genital papillae on segments 6���7, not always conspicuous (Figs 15 D; 16 C). Pygidium smooth to slightly crenulate (Figs 12 A���D, N���O; 15 C). Variation. Some specimens, such as paratype AM W. 45831, examined under SEM, have a single pair of neuropodia bearing acicular spines, on segment 8, instead of two pairs, on segments 7 and 8. Those specimens are otherwise similar to animals with acicular spines on segments 7 and 8, and so we consider this as a variable character in T. akares n. sp. In addition, in specimens with two pairs of neuropodia with acicular spines, those of the first pair are always much shorter than spines from the second pair, indicating that they may be so small as to be difficult to see under the SEM, as they do not protrude from the body wall. Remarks. According to Parapar & Hutchings (2014), there is another species of Terebellides having two pairs of neuropodia with spines, on segments 7 and 8, T. bigeniculatus Parapar, Moreira & Helgason, 2013. Terebellides bigeniculatus differs from T. akares n. sp. by having branchial lamellae distally smooth, lacking papillae (visible under light microscopy); neuropodial spines of segments 7 and 8 similar to each other, bent at right angle and gently tapering; abdominal neuropodia as rounded pinnules, with uncini originating all around and separated from each other by deep grooves; and smaller nephridial and genital papillae of segments 6���7. In contrast, branchial lamellae of T. akares n. sp. have a distal row of scattered papillae on both sides; neuropodial spines of segment 7 are bayonet-like chaetae and those of segment 8 are bent at right angle and gently tapering; and abdominal neuropodia are wider than long, with uncini only on top, with shallower grooves in between. Currently five species are recorded from Australia and none from the Great Barrier Reef. Of these, only T. narribri Hutchings & Peart, 2000 and T. woolawa Hutchings & Peart, 2000 have five branchial lobes, all the others have four pairs. Terebellides akares n. sp. can be distinguished from T. woolawa that has all branchial lobes similar in size in contrast to our new species where the posterior pair is much shorter. Terebellides narribri has only the first pair of notopodia reduced, in contrast, our new species has the first two pairs much shorter and with short chaetae, whereas in T. narribri it is only the podia which are reduced, not the length of the chaetae. Both these previously described Australian species only have the first pair of neuropodia with acicular chaetae, whereas T. akares n. sp. has the first two pairs of neuropodia with such chaetae. Etymology. The specific name ��� akares ��� refers to the distinctly short abdomen, with compacted segments, from the Greek word ��� akares ���, meaning short. Habitat. In amongst coral rubble in the intertidal zone. Type locality. Reef flat at south end of Coconut Beach, 14 �� 41 ' 42 "S, 145 �� 28 ' 11 ���E, Lizard Island, Great Barrier Reef, Queensland, Australia. Distribution. Known only from Lizard Island and North Direction Island., Published as part of Hutchings, Pat, Nogueira, Jo��o Miguel Matos & Carrerette, Orlemir, 2015, Telothelepodidae, Thelepodidae and Trichobranchidae (Annelida, Terebelliformia) from Lizard Island, Great Barrier Reef, Australia, pp. 240-274 in Zootaxa 4019 (1) on pages 261-266, DOI: 10.11646/zootaxa.4019.1.12, http://zenodo.org/record/253393, {"references":["Parapar, J. and Hutchings, P. (2014). Redescription of Terebellides stroemii (Polychaeta, Trichobranchidae) and designation of a neotype. Journal of the Marine Biological Association of the United Kingdom, 96 (2), 323 - 337.","Hutchings, P. A. & Peart, R. (2000) A revision of the Australian Trichobranchidae (Polychaeta). Invertebrate Taxonomy, 14 (2), 225 - 272. http: // dx. doi. org / 10.1071 / IT 98005"]}

Polychaete assemblages were studied from samples taken in the Southwestern Atlantic, between 34°S and 38°S (Argentinean Biogeographical Province) during 1993, 2001 and 2002 from a series of oceanographic cruises in mixohaline to oceanic waters. Polychaetes represented almost 25% (number of taxa) of the macrobenthic assemblages; 57 taxa corresponding to 29 families were identified. The MDS plot shows an ordination of samples according to the following areas: the central estuary and mouth of Río de la Plata (group 1), the coastal shelves of Uruguay and Argentina and the transect off the mouth of Río de la Plata (groups 2 and 3) and other coastal stations from both countries (groups 4 and 5). The abiotic variable that best explained the distribution pattern (BIO-ENV analysis) was the bottom salinity, while the best combination included 2 variables: bottom salinity and type of bottom. Trophic diversity increased with salinity. The distributional range of four species: Sabellaria bellis Hansen, 1882; Travisia amadoi Elías et al., 2003a: Terebellides lanai Solis-Weiss et al., 1991 and Aglaophamus uruguayi Hartman, 1953, was extended. Se estudiaron las agrupaciones de poliquetos a partir de muestras recogidas en el Atlántico Sudoccidental, entre 34ºS y 38ºS (Provincia Biogeográfica Argentina) durante los años 1993, 2001 y 2002, en el marco de campañas oceanográficas llevadas a cabo desde aguas mixohalinas hasta marinas. Los poliquetos representan casi el 25% (número de taxones) de la agrupación macrobentónica; fueron identificados 57 taxones pertenecientes a 29 familias. El ordenamiento multidimensional (MDS) de estaciones distingue diferentes áreas: estuario central y boca del Río de la Plata (grupo 1), plataformas costeras de Uruguay y Argentina, y transecta fuera del Río de la Plata (grupos 2 y 3) y otras estaciones costeras de ambos países (grupos 4 y 5). La variable abiótica que mejor explicó el patrón de distribución (análisis BIO-ENV) fue la salinidad de fondo; la mejor combinación incluyó dos variables: salinidad de fondo y tipo de fondo. La diversidad trófica incrementó con la salinidad. Se extiende el rango de distribución de cuatro especies: Sabellaria bellis Hansen, 1882, Travisia amadoi Elías et al., 2003a, Terebellides lanai Solis-Weiss et al., 1991 y Aglaophamus uruguayi Hartman, 1953. &nbsp

To assess the phylogenetic interrelationships of Trichobranchinae (Polychaeta: Terebellidae), we present the results of a cladistic analysis based on morphological characters coded as contingent. We also present an alternate way to number anterior segments, based on a reinterpretation of prostomial and peristomial morphologies in different genera. The ingroup terminals included 28 species, and the outgroup included one species of Ampharetidae and four species belonging to other subfamilies of Terebellidae. The monophyly of Trichobranchinae is clearly supported by the presence of long shafted uncini in thoracic neuropodia and by the absence of ventral shields. Species of Terebellides share lamellate branchiae, uncini with a long and narrow manubrium without denticles and uncini with a long and sharp main fang in the eighth segment. Species of Octobranchus share subquadrate branchiae on segments 3, 4 and 5, notopodia first present from segment 4, and uncini with a long shafted manubrium first present from segment 6. The autapormophy for Unobranchus is the presence of a single filiform branchia on segment 3. Artacamella falls into one of the Trichobranchus clades and is treated as a junior synonym of the latter.

Terebellides sepultura sp. nov. is described from the continental shelf bottoms off southern Brazil. Terebellides carmenensis Solis-Weiss, Fauchald & Blankensteyn, 1991 is newly recorded for the Brazilian coast and notes on T. anguicomus F. Müller, 1858 and T. klemani Kinberg, 1867 are provided. A key to 28 species of Terebellides is given.

Terebellides Sars, 1835 intoshi Caullery, 1915d: Halmahera Sea. NML 1497, 1506, 1513, 1544, 1549, 1595 jorgeni Hutchings, 2007: S Bali. ZMUC 1840, 1841 sieboldi Kinberg, 1867: Bangka Strait, Indonesia. SMNH 6879–6881 ypsilon Grube, 1878: Bohol, Philippines. MPW 409, ZMB 1539, Published as part of Salazar-Vallejo, Sergio I., Carrera-Parra, Luis F., Muir, Alexander I., León-González, Jesús Angel De, Piotrowski, Christina & Sato, Masanori, 2014, Polychaete species (Annelida) described from the Philippine and China Seas, pp. 1-68 in Zootaxa 3842 (1) on page 45, DOI: 10.11646/zootaxa.3842.1.1, http://zenodo.org/record/4928482, {"references":["Caullery, M. (1915 d) Sur les Terebellides Malmgren du Siboga et les terebelliens voisins. Bulletin de la Societe Zoologique de France, 40, 111 - 116.","Hutchings, P. A. (2007) New deep-sea species of Terebellidae and Trichobranchidae (Polychaeta) (Sedentary species 3). Galathea Reports, 21, 75 - 90.","Kinberg, J. G. H. (1867) Annulata nova (continuatio). Ofversigt af Koniglich Vetenskaps-Akademiens Forhandlingar, 23, 337 - 357."]}

Terebellomorpha is a clade of predominantly tube-dwelling polychaetes, some of whose species are very abundant and whose habitats range from shallow to very deep waters. The group contains five families (Terebellidae, Ampharetidae, Pectinariidae, Trichobranchidae and Alvinellidae). This study of their inter-relationships uses DNA sequence data from five gene segments. Including outgroups, sequences were available for 15 species for 15 U2 snRNA, 14 for Histone H3, 23 for the D1 expansion region of 28S rDNA, 15 for the D9-10 region of 28S rDNA and 17 for subunit I of cytochrome oxidase. Outgroups included representatives of the polychaete families Cirratulidae, Sabellidae and Siboglinidae, and the clitellate Lumbricus. These sequences include eight GenBank entries for 28S D1 and one for CO1.Generally, and in all analyses restricted to the data collected in this laboratory, but including all of these, Terebellomorpha is monophyletic. Within Terebellomorpha, the single maximum parsimony tree indicates that Alvinellidae (all data from GenBank) belongs to a clade with Terebellidae and some Trichobranchidae, contradicting morphological expectations. Terebellidae is paraphyletic with respect to Trichobranchus, this being associated with the subfamily Thelepodinae. The second trichobranchid genus Terebellides (for which only 28S D1 data is available from GenBank) is topologically very distinct to Trichobranchus. Additional data are needed to establish the family's monophyly. Also within Terebellidae, subfamily Terebellinae is paraphyletic with respect to Polycirrinae, supporting the suggestion that this subfamily's morphological simplicity is derived.