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ESM file 1 consists of two tables, which contain details of the collection metadata for each museum or university collection and phyla. Table S1.1 indicates the number of records available prior to data curation and filtering for the three analysed phyla. Note that the number of initial records reported in the main manuscript is higher because it includes records for other phyla. Table S1.2 indicates the number of records after data curation and filtering. These numbers equal the numbers in the main manuscript.

Temporal distribution of records for all species in the investigated collection database as in Figure 4 of the main manuscript. The years 1912 and 1991 (the end of two intense collecting efforts) are indicated by grey vertical lines. Colors denote supraspecific taxa: Crustacea (blue), Mollusca (green) and Echinodermata (red).

Temporal distribution of records for all species in the investigated collection database as in Figure 4 of the main manuscript. The years 1912 and 1991 (the end of two intense collecting efforts) are indicated by grey vertical lines. Colors denote supraspecific taxa: Crustacea (blue), Mollusca (green) and Echinodermata (red).

ESM file 3 shows two maps for each species; one map for all occurrences prior to 1912, and one map for all occurrences after 1912. The occurrences are colored by the supraspecific taxon: Crustacea (blue), Echinodermata (red), and Mollusca (green).

Mauretanaspis longichaeta gen. et spec. nov. urn:lsid:zoobank.org:act: AA378791-074B-4349-B2E2-235FD632E35C Figs 1���4, Table 1 Etymology The species epithet is a combination of the Latin ��� longus ��� (= ���long���) and the Greek ��� chaeta ��� (= ���bristle���) characterizing the striking length of the posteriormost lateral chaetae of the ventro-caudal shield. Material examined Holotype NORTHEAST ATLANTIC ��� Off Mauritania ��� 1 complete specimen (body slightly contracted, introvert fully everted, length 5.0 mm, width 1.6 mm, abdomen length 3.0 mm, left shield plate length 1.2 mm, width 0.9 mm); Block C9, stn C9-15 (B3); 18��21.27��� N, 17��57.44��� W; depth 2712 m; 24 Oct. 2018; deepsea mud, box core; MNHN-IA-TYPE 2005. Paratype NORTHEAST ATLANTIC ��� Off Mauritania ��� 1 complete specimen (introvert partly retracted, length 3.5 mm, width 1.8 mm, abdomen length 1.0 mm, left shield plate length 1.2 mm, width 1.2 mm); Block C9, stn C9-15 (B1); 18��21.27��� N, 17��57.44��� W; depth 2712 m; 24 Oct. 2018; deep-sea mud, box core; SMF 27777. Other material NORTHEAST ATLANTIC ��� Off Mauritania ��� 1 spec. (bad condition, anterior end retracted, length n.d., width 2.6 mm, abdomen length 3.7 mm, left shield plate length 1.6 mm, width 1.0 mm); Block C9, stn C9-20 (B1); 18��26.91��� N, 17��59.25��� W; depth 2714 m; 27 Oct. 2018; deep-sea mud, box core; SMF 27776. SOUTHEAST ATLANTIC ��� Off Angola ��� 1 spec. (juvenile with capillary chaetae in pre-shield segments, without gonopodial lobes, anterior end missing, length n.d., width 0.35 mm); stn S48-03A; 6��53.107��� S, 10��30.762��� E; depth 2935 m; 7 Sep. 2018; box core; MNHN-IA-PNT 120 ��� 1 spec. (juvenile, anterior end damaged, length n.d., width 0.65 mm, left shield plate length 0.5 mm); stn S48-08A; 6��59.047��� S, 10��36.748��� E; depth 2736 m; 9 Sep. 2018; box core; SMF 28061 ��� 1 spec. (gonopodial lobes present, length 3.2 mm, width 1.1 mm, left shield plate length 1.1 mm); stn S48-09C; 7��4.931��� S, 10��13.003��� E; depth 4373 m; 14 Sep. 2018; box core; SMF 28062 ��� 1 spec. (juvenile, body wall translucent, with chaetae in some abdominal segments, without gonopodial lobes, length 2.5 mm, width 0.9 mm); stn S48-14C; 7��10.998��� S, 10��13.064��� E; depth 4363 m; 14 Sep. 2018; box core; MNCN 16.01/18762 ��� 1 spec. (strongly bent and wrinkled, gonopodial lobes not seen, posteriormost lateral chaetae ca 4�� length of body, length n.d., width n.d., left shield plate length 1.0 mm); stn S48-23A; 7��23.159��� S, 10��24.921��� E; depth 4375 m; 15 Sep. 2018; box core; MNCN 16.01/18763 ��� 1 spec. (juvenile, body wall translucent, anterior end missing); stn S48-23B; 7��23.159��� S, 10��24.921��� E; depth 4375 m; 15 Sep. 2018; box core; DBUA0002349.01 ��� 1 spec. (anterior end retracted, gonopodial lobes retracted but visible, length n.d., width n.d., left shield plate length 1.0 mm); stn S48-26C; 6��58.715��� S, 10��17.741��� E; depth 4191 m; 10 Sep. 2018; box core; DBUA0002349.02. Description Based on holotype (Figs 1, 2 A���C, 3A���C), complete specimen (body slightly contracted but introvert fully everted), complemented by paratype (Fig. 4 A���C) where indicated. BODY COLOUR. Pale yellow. PROSTOMIUM. Small hemispherical cupule, pale, semi translucent. Eyes absent. PERISTOMIUM. Surrounding mouth projecting to level of prostomial cupule, about 1.5 �� diameter of prostomium. Mouth small, round. INTROVERT. First three chaetigers each with 15���17 hooks on either side (segment 1: left 9 +6 small, right 8 +8; 2: left 9+ 7, right 9 +8; 3: left 9+6, right 8+7); hooks golden, tapering to blunt transparent tip; decreasing gradually in length and diameter from dorsal to ventral in each fascicle. Ventralmost 6���8 hooks small to minute. Hooks equally spaced in fully everted introvert (Figs 1, 2 A���C, 3A, 4A). Minute drop-shaped papillae in single rows parallel to segmental folds dorsally in segments 1���3. Body damaged ventrally on segments 3���4 with oesophagus protruding (Figs 1, 2C, 3A). Gonopodial lobes small, digitiform, protruding ventrolaterally from intersegmental groove between segments 5 and 6 (Figs 1, 4 A���B). ANTERIOR ABDOMEN (PRE- SHIELD REGION). Comprising eight segments. Body papillae minute, round, forming single rows close to intersegmental folds, sometimes obscured by sediment particles (Figs 1, 4B). Most pre-shield segments of holotype with smooth median surface on ventral side, possibly abraded, and few, short, filamentous papillae on lateral sides; in paratype median surface papillated (Figs 1, 4A). Few filamentous papillae among adhering sediment particles on segments anterior to branchial plates. VENTRO- CAUDAL SHIELD. Densely covered by fine, firmly adhering sediment particles. Shield colour light brown, obscured by dense cover of sediment. Colour most intense around anterior end of median suture (sediment abraded in holotype, not abraded in paratype) (Figs 3B, 4A). No structures (ribs, concentric rings) visible due to sediment cover. Anterior margins slightly rounded, anterior depression shallow, covered by sediment; anterior keels faintly visible (Fig. 3B), not exposed. Lateral margins rounded, strongly bent towards dorsal side, not forming free, stiff or pliable margins, but rather merging into integument. Posterior fan and lateral notch not discernible due to sediment cover; shallow median notch (more pronounced in paratype (Fig. 4A, C)). Suture defined in anterior �� of shield, moderately deep with distinct lateral borders (Figs 3B, 4A). MARGINAL SHIELD CHAETAE. Yellow; 20 lateral fascicles, i.e., 9���11 fascicles per side, with 4���6 capillary chaetae each. Chaetae arranged in oblique rows, increasing gradually in length posteriorly within each fascicle and among fascicles (Figs 2C, 3C, 4 B���C); chaetae of posteriormost lateral fascicle very long, equalling body length (Figs 2C, 3D). Six pairs of fascicles posterior to shield (i.e., posterior shield chaetae), each with 1���3 (mostly 2) yellow capillaries of varying length and different strength (Figs 3B, 4A, C); lateralmost longest, equalling length of shield. Peg chaetae absent. BRANCHIAL FILAMENTS. Numerous, increasing in length posteriorly, opaque, coiled to various extent. BRANCHIAL PLATES. Brownish, forming ovoid to trapezoidal region, densely covered by filaments, filamentous papillae and sediment grains (Fig. 3C). Distribution Northeast to Southeast Atlantic, from off Mauritania to Angola, in deep-sea mud, in depths of 2700��� 4400 m. Remarks Mauretanaspis longichaeta gen. et spec. nov. can be distinguished from all other known species of Sternaspidae by the following combination of characters: introvert hooks tapering, tips transparent; pre-shield region with eight segments; ventro-caudal shield densely covered with fine, firmly adhering sediment obscuring shield structures except median suture. Mauretanaspis longichaeta gen. et spec. nov. is the only sternaspid with chaetae in posteriormost lateral fascicles equalling body length. In one specimen collected off Angola (MNCN 16.01/18763), posteriormost lateral chaetae even measure about 4�� the length of the body. Several specimens from off Angola (SMF 28062, MNCN 16.01/18762, MNCN 16.01/18763, DBUA0002349.01) show black pigment presumably from surrounding sediment included in sediment cover and among sand grains in the branchial region. Black particles are scattered on the shield forming spots of different sizes. We compared our material to a specimen collected off Northwest Africa in 1320 m depth and identified as Sternaspis scutata (Ranzani, 1817) by Kirkegaard (2001: 396). The specimen, deposited in the collections of the Natural History Museum of Denmark (NHMD 662048), was not available for study, but pictures of it were kindly made available to us by S. Salazar-Vallejo. Unfortunately, the animal is in very bad condition: anterior hooks tapering to fine tips, number of pre-shield segments and gonopodial lobes not distinguishable, shield completely covered by fine sediment obscuring surface structures, shield without free margins, length of lateral and posterior shield chaetae indeterminable. It remains uncertain whether the sediment can be removed from the shield without damaging it, but with regard to shield characters visible in the pictures available, the specimen appears incorrectly identified as Sternaspis scutata. However, due to its bad condition we cannot identify it any further. Identification key to Sternaspidae with sediment particles firmly attached to ventro-caudal shield ( Caulleryaspis (in part) and Mauretanaspis gen. nov.) (adapted from Salazar- Vallejo 2017) 1. Shield with anterior depression deep; peg chaetae robust................................................................ 2 ��� Shield with anterior depression shallow; peg chaetae absent........................................................... 3 2. Shield with anterior margins angular; peg chaetae forming thick, large spines.......................................................... Caulleryaspis gudmundssoni Sendall & Salazar-Vallejo, 2013 (N Atlantic, Iceland) ��� Shield with anterior margins rounded; peg chaetae forming thin, small spines..................................... Caulleryaspis fauchaldi Salazar-Vallejo & Buzhinskaja 2013 (NE Pacific, Oregon to California) 3. Seven pre-shield segments; chaetae in posteriormost lateral fascicles about length of shield............................................... Caulleryaspis laevis (Caullery, 1944) (Indo-Pacific, Indonesia) ��� Eight pre-shield segments; chaetae in posteriormost lateral fascicles equalling body length.......................... Mauretanaspis longichaeta gen. et spec. nov. (NE and SE Atlantic, Mauritania to Angola), Published as part of Fiege, Dieter & Barnich, Ruth, 2020, A new genus and species of Sternaspidae (Annelida: Polychaeta) from the deep eastern Atlantic, pp. 1-13 in European Journal of Taxonomy 699 on pages 4-10, DOI: 10.5852/ejt.2020.699, http://zenodo.org/record/3981057, {"references":["Ranzani C. 1817. Descrizione di una nova specie del genere Thalassema. Opusculi Scientifici I: 112 - 116.","Kirkegaard J. B. 2001. Deep-sea polychaetes from northwest Africa, including the description of a new species of Neopolynoe (Polynoidae). Journal of the Marine Biological Association of the United Kingdom 81: 391 - 397. https: // doi. org / 10.1017 / S 0025315401004003","Sendall K. & Salazar-Vallejo S. I. 2013. Revision of Sternaspis Otto, 1821 (Polychaeta, Sternaspidae). ZooKeys 286: 1 - 74. https: // doi. org / 10.3897 / zookeys. 286.4438","Salazar-Vallejo S. I. & Buzhinskaja G. N. 2013. Six new deep-water sternaspid species (Annelida, Sternaspidae) from the Pacific Ocean. ZooKeys 348: 1 - 27. https: // doi. org / 10.3897 / zookeys. 348.5449","Caullery M. 1944. Polychetes sedentaires de l'expedition du Siboga. Ariciidae, Spionidae, Chaetopteridae, Chlorhaemidae, Opheliidae, Oweniidae, Sabellariidae, Sternaspidae, Amphictenidae, Ampharetidae, Terebellidae. Siboga-Expeditie 24 (2): 1 - 204. Brill, Leiden."]}

Mauretanaspis gen. nov. urn:lsid:zoobank.org:act: 1FC8F8ED-C7A3-4EC9-AB69-6A0147632D23 Table 2 Type species Mauretanaspis longichaeta gen. et spec. nov. designated herein. Diagnosis Sternaspids with introvert hooks tapering. Eight segments between gonopodial lobes and shield (i.e., preshield region). Ventro-caudal shield densely covered with firmly adhering fine sediment, which cannot be brushed off. Due to sediment cover no shield structures like ribs or concentric rings visible except median suture. Shield with lateral margins strongly bent towards dorsal side, merging into integument. Peg chaetae absent. Etymology The genus name is a combination of the Latin name for the type locality off the Northwest African state Mauritania (i.e., Mauretania, Lat.) and the Greek word ��� aspis ��� (= ���shield���); gender: feminine. Remarks Mauretanaspis gen. nov. differs in the combination of characters from the other genera of Sternaspidae. The shield is completely and firmly covered by sediment, as in several species of Caulleryaspis, but it has eight pre-shield segments; peg chaetae (i.e., a dense group of short chaetae covered by a common sheath) are absent, while Caulleryaspis has seven pre-shield segments and peg chaetae are present. In Caulleryaspis nuda peg chaetae are absent, but according to Drennan et al. (2019) this species possibly belongs to the genus Sternaspis (see ���Discussion���). Petersenaspis has eight pre-shield segments and peg chaetae are absent, as in Mauretanaspis gen. nov., but the shield is not covered by sediment and the introvert hooks are subdistally expanded or spatulate while hooks in Mauretanaspis gen. nov. are tapering (Table 2)., Published as part of Fiege, Dieter & Barnich, Ruth, 2020, A new genus and species of Sternaspidae (Annelida: Polychaeta) from the deep eastern Atlantic, pp. 1-13 in European Journal of Taxonomy 699 on page 3, DOI: 10.5852/ejt.2020.699, http://zenodo.org/record/3981057, {"references":["Drennan R., Wiklund H., Rouse G. W., Georgieva M. N., Wu X., Kobayashi G., Yoshino K. & Glover A. G. 2019. Taxonomy and phylogeny of mud owls (Annelida: Sternaspidae), including a new synonymy and new records from the Southern Ocean, North East Atlantic Ocean and Pacific Ocean: challenges in morphological delimitation. Marine Biodiversity 49: 2659 - 2697. https: // doi. org / 10.1007 / s 12526 - 019 - 00998 - 0"]}

Syllis qamhiyn n.sp. Figures 2–6 urn:lsid:zoobank.org:act: A270D267-0901-4185-80E4-E6D0AAC48A49 Material examined. Holotype (SMF 26713) Soc /ST–726, Ras Qataninh Bay, 12º21.293’N 53º32.659’E, under stones and coral rubble, 8–10 m, coll. T. Wehe 9.4.2000. 1 paratype, same collection data (NHCY 0018); 1 paratype prepared for SEM, Soc/ST–725, Ras Qataninh Bay, dredge, 12º21.789’N 53º31.399’E to 12º21.780’N 53º31.390’E, 18–20 m, coll. T. Wehe 09.04.2000, (SMF 26714, SEM-stub 1311). Diagnosis. Conspicuously thick and short dorsal cirri filled with gelatinous substance; reduced number of compound chaetae from midbody to posterior parapodia, with enlarged shafts and short blades, which become almost unidentate; blades not fused to shafts. Description. Holotype complete specimen, 17.5 mm long, 0.69 mm wide, with 151 chaetigers (Fig. 2A). One incomplete paratype with 134 chaetigers, and other complete, Paratype (SMF 26714), 18.5 mm long, 0,5 mm wide, with 160 chaetigers (Fig. 4B). Body long and slender, filiform, without colour pattern (Figs 2A, B, C; 4B). Prostomium semicircular to oval (Figs 2A; 5A); four small eyes in trapezoidal arrangement. Palps similar in length to prostomium. Median antenna arising between anterior eyes, with 12–13 articles, shorter than combined length of prostomium and palps. Lateral antennae same length as median antenna, with 13 articles each (Fig. 2A). Peristomium dorsally shorter than subsequent segments (Figs. 2A; 5B). Dorsal tentacular cirri about 15–21 articles each; ventral tentacular cirri about 13–14 articles each. Dorsal parapodial cirri relatively thin on anterior segments, alternating relatively long (0.3 mm) and short (0.2 mm); longer cirri similar in length to body width at corresponding chaetiger, with about 17–19 articles, shorter ones about 7–11 articles each (Fig. 2A); from midbody posteriorwards, dorsal cirri shorter than body width, each cirrus thicker in midlength, with about eight well-marked articles, with acute article distally (Fig. 2 A–D); most articles of these dorsal cirri filled with gelatinous substance (Fig. 2D), articles covered by small pores (Fig. 5F). Ventral cirri oval, shorter than parapodial lobes (Figs 2D; 6D). Ventral area of parapodia with almost circular area of pores (Fig. 6 C–E) and internal gland (Fig. 2D). Compound chaetae as heterogomph falcigers; anterior parapodia with about 10 falcigers each; falcigers with slender bidentate blades, proximal tooth distinctly shorter than distal one, and short spines on margin; blades with dorsoventral gradation in length, 42–20 μm long (Figs 3A; 5C, D). Number of chaetae per parapodium progressively diminishing posteriorly, 4–5 in midbody (Figs 3C; 5E, G, H) and 3–5 on mid-posterior and posterior parapodia (Figs 3E; 6 A–B), shafts becoming larger and blades shorter and minutely bidentate, with proximal tooth much smaller than distal one (Fig. 3E). Midbody falcigers with blades 20–19 μm long, posterior body falcigers with blades similar, about 19 μm long. Dorsal and ventral simple chaetae not seen. Anterior parapodia with five slender aciculae each, distally rounded (Fig. 3B), three in midbody parapodia (Fig. 3D); posterior parapodia with two distally oblique aciculae each (Fig. 3F). Pharynx long, extending through about 13 segments (Figs 2A; 4B); pharyngeal tooth elongated, conical, acute, on anterior margin of pharynx (Figs 2A, 4A). Proventricle shorter than pharynx, through 9–10 segments (Fig. 2A), with about 48–50 muscle cell bands. Pygidium small, with two anal cirri, with 7–8 articles each (Fig. 6F). Etymology. The name of the species refers to Dendrosicyos socotrana, the only species of Cucurbitaceae growing into tree form and original from Socotra Island. Its trunk resembles the shape of midbody cirri of S. qamhiyn n.sp. In soqotri language it is named qamhiyn. Remarks. Syllis qamhiyn n.sp. is characterized by having short, thick, distally acute dorsal cirri on midbody and posterior parapodia, and reduced number of falcigers in these parapodia, with enlarged shafts and short, almost unidentate blades, not fused to shafts. Syllis qamhiyn n.sp. belongs to the same group of species of Syllis armillaris (O. F. Müller, 1771) and related species, the latter considered cosmopolitan but likely a species complex. The mid- and posterior body falcigers of Syllis armillaris also have almost unidentate blades, but they are not so short and the shafts are not as enlarged as in Syllis qamhiyn n.sp. (San Martín 2003); furthermore, the mid- and posterior body dorsal cirri of Syllis armillaris are enlarged, but not so much as in Syllis qamhiyn n.sp. Similar differences are between Syllis qamhiyn n.sp. and S. pseudoarmillaris Nogueira & San Martín, 2002 from Brazil (Nogueira & San Martín 2002); S. pseudoarmillaris has fewer number of articles on midbody dorsal cirri and the compound chaetae of these parapodia are clearly bidentate, with not enlarged shafts; furthermore, the pharynx and proventricle are longer in S. qamhiyn n.sp. Syllis gracilis Grube, 1840, also considered a cosmopolitan species, and S. picta (Kinberg, 1886), from the Indo-Pacific (including the Red Sea), have similar bodies, with enlarged mid- and posterior body dorsal cirri, but in these species at least one of the compound chaetae on these parapodia have fused blade and shaft (San Martín 2003; Álvarez-Campos et al. 2015; 2017). Habitat. Under stones and coral rubble from 8– 20 m. Distribution. Only known from Socotra Archipelago. Type locality. Ras Qataninh Bay, Socotra Island.

Syllis compacta Gravier 1900 Syllis (Typosyllis) compacta Gravier, 1900: 165, pl. IX, fig. 11, text-fig. 33���38. Syllis compacta.��� L��pez et al. 1996: 110, fig. 3; San Mart��n 2003: 433, figs 238���239. Non Syllis golfonovoensis (Hartman-Sch��der, 1962): 87���89, figs 60���62; San Mart��n 1984: 395, figs 104, 105. Material examined. Rush 009, Samha, 12��10.317���N 53��04.383���E, upper intertidial among algae, coll. T. Wehe 7.4.2000, 2 specimens (SMF 26700). Habitat. Intertidal, amongst algae. Typically found in intertidal pools, specially on calcareous concretions of biological origin, like vermetid reefs, coral blocks, Posidonia oceanica rhizomes, photophilic and sciaphilic algae (L��pez et al. 1996). Distribution. Djibouti, Gulf of Aden (Gravier 1900). Adriatic Sea, Turkish Aegean Sea, Ionian Sea, North West Italy, East and western Mediterranean Sea, North East Atlantic, East coast of Spain (Musco & Giangrande 2005). New record for Socotra. Type locality. Djibouti, Gulf of Aden., Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2020, New species and records of the genus Syllis Savigny in Lamarck, 1818 (Annelida: Syllidae) from Socotra Archipelago (Indian Ocean), pp. 73-88 in Zootaxa 4742 (1) on page 78, DOI: 10.11646/zootaxa.4742.1.4, http://zenodo.org/record/3674479, {"references":["Gravier, C. (1900) Contribution a l'etude des annelides polychetes de la Mer Rouge. Premiere partie. Nouvelles Archives du Museum d'Histoire Naturelle, Paris, 2, 137 - 282. https: // doi. org / 10.5962 / bhl. part. 9306","Lopez, E., San Martin, G. & Jimenez, M. (1996) Syllinae (Syllidae, Annelida, Polychaeta) from Chafarinas Islands (Alboran Sea, W. Mediterranean). Miscellania Zoologica, 19 (1), 105 - 118.","San Martin, G. (2003) Annelida Polychaeta II. Syllidae. In: Ramos, M. A. et al. (Eds.), Fauna Iberica. Vol. 21. Museo Nacional de Ciencias Naturales, CSIC, Madrid, pp. 1 - 554.","Musco, L. & Giangrande, A. (2005) Mediterranean Syllidae (Annelida: Polychaeta) revisited: biogeography, diversity and species fidelity to environmental features. Marine Ecology Progress Series. 304: 143 - 153 + 4 pp. Supplementary appendix. https: // doi. org / 10.3354 / meps 304143"]}

Syllis broomensis (Hartmann-Schr��der, 1979) Typosyllis (Langerhansia) broomensis Hartmann-Schr��der, 1979: 88, figs 50���56; 1984: 18; 1989: 23; 1990: 48; 1991: 32. Typosyllis broomensis.��� Licher 1999: 70, fig. 32. Typosyllis (Langerhansia) cervantensis.��� Hartmann-Schr��der 1981, synonymized by Licher 1999: 70. Syllis broomensis.��� ��lvarez-Campos et al. 2015: 302, figs 1, 2. Material examined. Soc/ST���16, MAP 64, SE of Qualansiyah, 12��40.264���N 53��27.204���E, from live colony of Stylophora sp., 6���7 m, coll. M. Apel 08.03.1999, 1 specimen (NHCY 0009). Soc/ST���18, MAP 78A, Qualansiyah Bay, 12��41.026���N 53��28.309���E, 5���6 m, coll. M. Apel 10.3.1999, 1 specimen (SMF 26699). Habitat. On live corals and sand. Mainly in coral rubble, coarse sand and algae (��lvarez-Campos et al. 2015). Distribution. Australia (Queensland; Western Australia; New South Wales); Philippines (Luz��n Island); New Zealand; Caribbean Sea (Cuba); (San Mart��n 1992; ��lvarez-Campos et al. 2015). Type locality. Broome, NW Australia., Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2020, New species and records of the genus Syllis Savigny in Lamarck, 1818 (Annelida: Syllidae) from Socotra Archipelago (Indian Ocean), pp. 73-88 in Zootaxa 4742 (1) on page 77, DOI: 10.11646/zootaxa.4742.1.4, http://zenodo.org/record/3674479, {"references":["Hartmann-Schroder, G. (1979) Zur Kenntnis des Eulitorals der australischen Kusten unter besonderer Berucksichtigung der Polychaeten und Ostracoden. Teil 2. Die Polychaeten der tropischen Nordwestkuste Australiens (Zwischen Port Samson im Norden und Port Hedland im Suden). Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 76, 75 - 218.","Licher, F. (1999) Revision der Gattung Typosyllis Langerhans, 1879 (Polychaeta: Syllidae). Morphologie, Taxonomie und Phylogenie. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 551, 1 - 336.","Hartmann-Schroder, G. (1981) Zur Kenntnis des Eulitorals der australischen Kusten unter besonderer Berucksichtigung der Polychaeten und Ostracoden. Teil 6. Die Polychaeten der tropisch-subtropischen Westkuste Australiens (Zwischen Exmouth im Norden und Cervantes im Suden). Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 78, 19 - 96.","Alvarez-Campos, P., San Martin, G. & Hutchings, P. (2015) The genus Syllis Lamarck, 1818 (Annelida, Syllidae) from Australia. Molecular analysis and re-description of some poorly-known species. Zootaxa, 4052 (2), 297 - 331. https: // doi. org / 10.11646 / zootaxa. 4052.3.2","San Martin, G. (1992) Syllis Savigny in Lamarck, 1818 (Polychaeta: Syllidae: Syllinae) from Cuba, the Gulf of Mexico, Florida and North Carolina, with a revision of several species described by Verrill. Bulletin of Marine Science, 51 (2), 169 - 196."]}

Syllis Savigny in Lamarck, 1818 Type species: Syllis monilaris Savigny in Lamarck, 1818, Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2020, New species and records of the genus Syllis Savigny in Lamarck, 1818 (Annelida: Syllidae) from Socotra Archipelago (Indian Ocean), pp. 73-88 in Zootaxa 4742 (1) on page 74, DOI: 10.11646/zootaxa.4742.1.4, http://zenodo.org/record/3674479, {"references":["Lamarck J. B. (1818) Histoire Naturelle des animaux sans vertebres, presentant les caracteres generaux et particuliers de ces animaux, leur distribution, leurs classes, leurs familles, leurs genres, et la citation des principales especes qui s'y rapportent; precedee d'une introduction offrant la determination des caracteres essentiels de l'animal, sa distinction du vegetal et des autres corps naturelles, enfin l'exposition des principes fondamentaux de la zoologie. Deterville, Paris, 5, 612 pp."]}

Syllis hyalina Grube, 1863 Syllis hyalina Grube, 1863: 45, pl. 4, fig. 8; San Mart��n 2003: 426, figs 234, 235. Typosyllis hyalina.��� Licher 1999: 199, pl. 86. Material examined. Rush 009, Samha, 12��10.317���N 53��04.383���E, upper intertidal among algae, 0.5 m, coll. T. Wehe 7.4.2000, 2 specimens (SMF 26709). Soc /ST���16, MAP 60, 12��40.264���N 53��27.204���E, from dead coral (Pocillopora sp.), 6���7 m, coll. M. Apel 8.3.1999, 1 specimen (SMF 26710). Soc /ST-110, Ras Adho (Ras Hammadara), 12��38.534���N 54��15.770���E, 7���12 m, coll. M. Apel 25.03.1999, 1 specimen (NHCY 0016). Habitat. Abundant in littoral areas on hard substrates, also present, but scarcer, in sandy bottoms (San Mart��n 2003). Found in Socotra in mixed coral assemblage: faviids, Astreopora, dead Porites, dead Acropora pallifera (dominant before the 1998 bleaching event). Distribution. Apparently cosmopolitan (San Mart��n 2003). New record for Socotra. Type locality. Losinj (= Lussin Island), Croatia., Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2020, New species and records of the genus Syllis Savigny in Lamarck, 1818 (Annelida: Syllidae) from Socotra Archipelago (Indian Ocean), pp. 73-88 in Zootaxa 4742 (1) on page 79, DOI: 10.11646/zootaxa.4742.1.4, http://zenodo.org/record/3674479, {"references":["Grube, A. E. (1863) Beschreibung neuer oder wenig bekannter Anneliden. Archiv fur Naturgeschichte, 29, 37 - 69. https: // doi. org / 10.5962 / bhl. part. 9306","San Martin, G. (2003) Annelida Polychaeta II. Syllidae. In: Ramos, M. A. et al. (Eds.), Fauna Iberica. Vol. 21. Museo Nacional de Ciencias Naturales, CSIC, Madrid, pp. 1 - 554.","Licher, F. (1999) Revision der Gattung Typosyllis Langerhans, 1879 (Polychaeta: Syllidae). Morphologie, Taxonomie und Phylogenie. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 551, 1 - 336."]}

Syllis crassicirrata (Treadwell 1925) Typosyllis crassi-cirrata Treadwell, 1925: 113, figs. 10A���C. Typosyllis crassicirrata.��� Hartman 1966: 198; Licher 1999: 196, fig. 85. Typosyllis (Typosyllis) crassicirrata.��� Hartmann-Schr��der 1979: 90, figs 62���66; 1980: 49; 1981: 25; 1987: 33; 1989: 20; 1992: 53. Syllis crassicirrata.��� ��lvarez-Campos et al. 2015: 306, figs 3, 4; Ba-Akdah et al. 2018: 3, figs 1, 2. Material examined. Soc/ST���95, MAP 95, Shanitan, 12��40.156���N 54��02.850���E, from dead Acropora, 8 m, coll. M. Apel 22.03.1999, 1 specimen (NHCY 0015). Soc /ST���16, MAP 60, 12��40.264���N 53��27.204���E, from dead Pocillopora, 6 ��� 7 m, coll. M. Apel 8.3.1999, 4 specimens (SMF 26703). Soc /ST���67, MAP 137B, Rhiy di-Hamri, 12��40.429���N 54��11.731���E, 7���9 m, coll. M. Apel 19.03.1999, 1 specimen (NHCY 0010). Soc /ST���67, MAP 136, Rhiy di-Hamri, E of Hawlaf, 12��40.429���N 54��11.731���E, 7���9 m, from dead Pocillopora damicornis, coll. M. Apel 19.3.1999, 2 specimens (SMF 26704). Soc /ST���706, Kal Farun, 12��26.049���N 52��08.07���E, 9.5���12.5 m, coll. M. Apel 3.4.2000, 2 specimens (SMF 26706). Soc /ST���37, MAP 154, Shanitan cold store, 12��40.156���N 54��02.850���E, 7���9 m, from dead Acropora sp., coll. M. Apel 21.03.1999, 1 specimen (NHCY 0012). Rush 018, Ras Eriyhan-Quariyeh, 12��38.924���N 54��14.387���E, 10���12 m, coll. T.Wehe 20.4.2000, 1 specimen (SMF 26702). Soc /ST-92, MAP 151, Hawlaf Bay off dune, 12�� 40.519���N 54��4.170���E, from dead colony of Acropora cf. valida, 4���5 m, coll. M. Apel 21.3.1999, 1 specimen (SMF 26705). Soc /ST-18, MAP 77, Qalansiyah Bay, 12�� 41.026���N 53��28.309���E, 5���6 m, coll. M. Apel 10.3.1999, 1 specimen (NHCY 0014). Soc /ST���726, Qataninh Bay, 12��21.293���N 53��32.659���E, under stones and coral rubble, 8���11 m, coll. T. Wehe 9.4.2000, 1 specimen (SMF 26707). Soc /ST���725, Ras Qataninh Bay, dredge, 12��21.789���N 53��31.399���E to 12��21.780���N 53��31.390���E, corals and algae on hard substrate, 18���20 m, coll. T. Wehe 09.04.2000, 1 specimen (NHCY 0013). Soc /ST���18, MAP 78A, Qualansiyah Bay, 12��41.026���N 53��28.309���E, 5���6 m, coll. M. Apel 10.3.1999, 13 specimens (SMF 26701). Habitat. Algae and coarse sediments, pioneer species on artificial panels (Ba-Akdah et al. 2018). Dead corals, rocky substrates. Distribution. Widely distributed in the Pacific and the Indian Ocean: Hawaii, Polynesia, New Zealand, Australia and Red Sea (Ba-Akdah et al. 2018). New record for Socotra. Type localty. Laysan Island, Hawaii., Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2020, New species and records of the genus Syllis Savigny in Lamarck, 1818 (Annelida: Syllidae) from Socotra Archipelago (Indian Ocean), pp. 73-88 in Zootaxa 4742 (1) on page 78, DOI: 10.11646/zootaxa.4742.1.4, http://zenodo.org/record/3674479, {"references":["Treadwell, A. L. (1925) Polychaetous Annelids of tropical central Pacific. Bulletin of the Bernice P. Bishop Museum, 27, 113 - 119.","Hartman, O. (1966) Polychaetous Annelids of the Hawaiian Islands. Bernice P. Bishop Museum Occasional Papers, 23, 163 - 252.","Licher, F. (1999) Revision der Gattung Typosyllis Langerhans, 1879 (Polychaeta: Syllidae). Morphologie, Taxonomie und Phylogenie. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 551, 1 - 336.","Hartmann-Schroder, G. (1979) Zur Kenntnis des Eulitorals der australischen Kusten unter besonderer Berucksichtigung der Polychaeten und Ostracoden. Teil 2. Die Polychaeten der tropischen Nordwestkuste Australiens (Zwischen Port Samson im Norden und Port Hedland im Suden). Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 76, 75 - 218.","Alvarez-Campos, P., San Martin, G. & Hutchings, P. (2015) The genus Syllis Lamarck, 1818 (Annelida, Syllidae) from Australia. Molecular analysis and re-description of some poorly-known species. Zootaxa, 4052 (2), 297 - 331. https: // doi. org / 10.11646 / zootaxa. 4052.3.2","Ba-Akdah, M. A., Satheesh, S., Al-Sofyani, A. M. A., Lucas, Y., Alvarez-Campos, P. & San Martin, G. (2018) Taxonomy of some species of the genus Syllis (Annelida: Syllidae: Syllinae) from the Red Sea found among the first colonizers of an artificial substrate. Marine Biological Research, 14 (8), 790 - 805. https: // doi. org / 10.1080 / 17451000.2018.1531133"]}

Syllis alternata Moore, 1908 Syllis alternata Moore, 1908: 323���325, text-fig. a���f, 324; Moore 1909: 321; San Mart��n & Vi��itez 1984: 153, figs 1, 2; ��inar 1999: 246, fig. 4.102; San Mart��n 2003: 354, figs 192, 193. Typosyllis alternata.��� Hartman 1948: 21; Imajima 1966: 273, text-fig. 58; Licher 1999: 253, fig. 106. Syllis (Typosyllis) alternata.��� Gardiner 1976: 141, figs 13b, c; Uebelacker 1984: 30���141, figs. 30���136. Material examined. Soc/ST 706 Kal Farun rock outcrop, 12��26.049���N 52��08.07���E, 9.5���12.5 m, coll. M. Apel, 03.04.2000, 1 specimen (SMF 26697). Habitat. In coralligenous concretions, algae, M��erl, Posidonia rhizomes, detritic bottoms, vermetid reefs, calcareous algae (San Mart��n 2003). Distribution. Northeastern Pacific Ocean, from Alaska to California. Chukchi Sea. Japan. Caribbean Sea. Gulf of M��xico. Northeastern Atlantic. Mediterranean Sea. Indian Ocean. Apparently cosmopolitan, mainly in the northern hemisphere, but some of these records are probably the result of misidentifications (Read & Fauchald 2019), and S. alternata may be a complex of species. New record for Socotra. Type locality. Vincinity of Naha Bay, Behm Canal, SO-Alaska., Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2020, New species and records of the genus Syllis Savigny in Lamarck, 1818 (Annelida: Syllidae) from Socotra Archipelago (Indian Ocean), pp. 73-88 in Zootaxa 4742 (1) on page 75, DOI: 10.11646/zootaxa.4742.1.4, http://zenodo.org/record/3674479, {"references":["Moore, J. P. (1908) Some Polychaetous Annelids of the Northern Pacific Coast of North America. Proceedings of the Academy of Natural Sciences of Philadelphia, 60, 321 - 364.","Moore, J. P. (1909) The polychaetous annelids dredged by the Albatross \" off the coast of California in 1904. I. Syllidae, Sphaerodoridae, Hesionidae, Phyllodocidae. Proceedings of the Academy of Natural Sciences of Philadelphia, 61, 321 - 351. https: // doi. org / 10.5962 / bhl. title. 12425","San Martin, G. & Vieitez, J. M. (1984) Anelidos Poliquetos de los rizomas de Posidonia oceanica en las costas de Cabo de Palos (Murcia, Espana). In: Boudouresque, C. F., Jeudy de Grissac, A. & Oliver, J. (Eds.), International Workshop on Posidonia oceanica beds. G. I. S. Posidonie Publication 1. G. I. S. Posidonie Publ., Marseille, pp. 149 - 157.","Cinar, M. E. (1999) Turkiye'nin Ege Denizi sahillerinde dadylym gosteren syllidae (Polychaeta-Annelida) turlerinin taksonomisi ve ekolojisi. PhD Thesis, Ege University, Izmir, 443 S.","San Martin, G. (2003) Annelida Polychaeta II. Syllidae. In: Ramos, M. A. et al. (Eds.), Fauna Iberica. Vol. 21. Museo Nacional de Ciencias Naturales, CSIC, Madrid, pp. 1 - 554.","Hartman, O. (1948) The polychaetous annelids of Alaska. Pacific Science, 2 (1), 1 - 58.","Imajima, M. (1966) The Syllidae (Polychaetous Annelids) from Japan (V). Syllinae (2). Publications of the Seto Marine Biological Laboratory, 14 (4), 253 - 294. https: // doi. org / 10.5134 / 175446","Licher, F. (1999) Revision der Gattung Typosyllis Langerhans, 1879 (Polychaeta: Syllidae). Morphologie, Taxonomie und Phylogenie. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 551, 1 - 336.","Gardiner, S. L. (1976) Errant polychaete annelids from North Carolina. Journal of the Elisha Mitchell Scientific Society, 91 (3), 77 - 220.","Uebelacker, J. M. (1984) Family Syllidae Grube, 1850. In: Uebelacker, J. M. & Johnson, P. G. (Eds.), Taxonomic guide to the polychaetes of the northern Gulf of Mexico. Vol. IV. Mobile, Barry A. Vittor and Associates, Alabama, pp. 1 - 151.","Read, G. & Fauchald, K. (Eds.) (2019) World Polychaeta database. Syllis Lamarck, 1818. World Register of Marine Species. Available from: http: // www. marinespecies. org / aphia. php? p = taxdetails & id = 129680 (accessed 24 July 2019)"]}

Syllis bouvieri Gravier, 1900 Figure 1 Syllis bouvieri Gravier, 1900: 163, pl. IX, fig. 40. Non Syllis bouvieri San Mart��n 1984: 374, pls. 96, 97. Material examined. Soc/ST���18, MAP 78A, Qualansiyah Bay, 12��41.026���N 53��28.309���E, 5���6 m, coll. M. Apel 10.3.1999, 1 specimen (NHCY 0008). Soc/ST���92, MAP 151, Hawlaf Bay (off dune), 12��40.519���N 54��04.170���E, from Acropora cf. valida, 4���5 m, coll. M. Apel 21.3.1999, 1 specimen (SMF 26698). Additional material examined. Holotype ( MNHN 0146). Djibouti, Gulf of Aden. Description. Body long and slender, without colour pattern, 10.5 mm long, 0.8 mm wide, with approximately 64���67 chaetigers. Prostomium semicircular; 4 small reddish eyes in open trapezoidal arrangement. Palps robust, similar in length to prostomium. Median antenna arising between anterior eyes, with 38���40 articles, longer than combined length of prostomium and palps. Lateral antennae shorter than median one, with 20���22 articles. Peristomium dorsally similar in length to subsequent segments (Fig. 1A); dorsal tentacular cirri with about 30���33 articles, slightly longer than median antenna; ventral tentacular cirri with about 15���16 articles, slightly shorter than lateral antennae. Dorsal parapodial cirri long, pointed distally, with well-marked articles; first pair with about 41���44 articles, longer than body width. Midbody dorsal parapodial cirri with a slight alternation in length, about 30���26 articles, slightly thicker than anterior ones. Parapodia conical, distally slightly bilobed; ventral parapodial cirri digitiform, shorter than parapodial lobes. Compound chaetae heterogomph, with one or two dorsalmost chaetae having slender, elongated blades with both teeth similar and usually with rounded space in between, and moderate spines on margin, lightly curved upward (Fig. 1B, D, F); remaining falcigers distinctly shorter, nine on anterior parapodia, progressively diminishing to seven on midbody and six on posterior parapodia, blades bidentate with similar teeth, and moderate to short curved spines on margin (Fig. 1B, D, F). Blades of falcigers with dorsoventral gradation in length; slender, dorsalmost elongated blades 36 ��m long on anterior parapodia, 47 ��m on midbody, 42 ��m long on posterior parapodia; remaining falcigers 30���23 ��m long on anterior parapodia, 26���25 ��m on midbody, 26���17 ��m long on posterior parapodia. Anterior parapodia with three slender aciculae each, distally rounded (Fig. 1C), reducing to two in midbody parapodia, one subdistally slightly inflated with small oblique tip (Fig. 1E); posterior parapodia with one acicula each, distally bent at almost right angle, with acuminated tip (Fig. 1G). Dorsal simple capillary chaetae on posterior parapodia, thin, acute, apparently unidentate (Fig. 1H). Ventral simple capillary chaetae bidentate with some short spines on inner margin (Fig. 1I). Pharynx long, through about 8���9 segments; pharyngeal tooth elongated, conical, acute, on anterior margin of pharynx (Fig. 1A). Proventricle through six segments, with about 30 muscle cell rows., Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2020, New species and records of the genus Syllis Savigny in Lamarck, 1818 (Annelida: Syllidae) from Socotra Archipelago (Indian Ocean), pp. 73-88 in Zootaxa 4742 (1) on page 75, DOI: 10.11646/zootaxa.4742.1.4, http://zenodo.org/record/3674479, {"references":["Gravier, C. (1900) Contribution a l'etude des annelides polychetes de la Mer Rouge. Premiere partie. Nouvelles Archives du Museum d'Histoire Naturelle, Paris, 2, 137 - 282. https: // doi. org / 10.5962 / bhl. part. 9306"]}

Syllis schulzi (Hartmann-Schr��der, 1960) Typosyllis schulzi Hartmann-Schr��der, 1960: 80, pl. 2, fig. 34, pl. 5, figs 35���37; Licher 1999: 140. Syllis (Typosyllis) schulzi.��� Ben-Eliahu 1977: 21, figs. 6a���i. Syllis schulzi.��� San Mart��n 2003: 364, fig. 198; Ba-Akdah et al. 2018: 8, fig. 5. Material examined. Soc/ST���16, MAP 60, 12��40.264���N 53��27.204���E, dead coral (Pocillopora sp.), 6���7 m, coll. M. Apel 8.3.1999, 2 specimens (SMF 26712). Soc/ST���16, MAP 61, SE of Qualansiyah, 12��40.264���N 53��27.204���E, dead coral, 5���6 m, coll. M. Apel 08.03.1999, 1 specimen (NHCY 0017). Habitat. Coral rubble, algae, vermetid reefs; pioneer on artificial panels. Intertidal and shallow depths. Distribution. Red Sea and Southern Mediterranean (Ba���Akdah et al. 2018). New record for Socotra. Type locality. Ghardaqa, Red Sea., Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2020, New species and records of the genus Syllis Savigny in Lamarck, 1818 (Annelida: Syllidae) from Socotra Archipelago (Indian Ocean), pp. 73-88 in Zootaxa 4742 (1) on page 85, DOI: 10.11646/zootaxa.4742.1.4, http://zenodo.org/record/3674479, {"references":["Hartmann-Schroder, G. (1960) Polychaeten aus dem Roten Meer. Kieler Meeresforschungen, 16, 69 - 125.","Licher, F. (1999) Revision der Gattung Typosyllis Langerhans, 1879 (Polychaeta: Syllidae). Morphologie, Taxonomie und Phylogenie. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 551, 1 - 336.","Ben-Eliahu, N. M. (1977) Polychaete cryptofauna from rims of similar intertidal vermetid reefs on the Mediterranean coast of Israel and in the Gulf of Eilat: Syllinae and Eusyllinae (Polychaeta Errantia: Syllidae). Israel Journal of Zoology, 26, 1 - 58.","San Martin, G. (2003) Annelida Polychaeta II. Syllidae. In: Ramos, M. A. et al. (Eds.), Fauna Iberica. Vol. 21. Museo Nacional de Ciencias Naturales, CSIC, Madrid, pp. 1 - 554.","Ba-Akdah, M. A., Satheesh, S., Al-Sofyani, A. M. A., Lucas, Y., Alvarez-Campos, P. & San Martin, G. (2018) Taxonomy of some species of the genus Syllis (Annelida: Syllidae: Syllinae) from the Red Sea found among the first colonizers of an artificial substrate. Marine Biological Research, 14 (8), 790 - 805. https: // doi. org / 10.1080 / 17451000.2018.1531133"]}

Syllis gerlachi (Hartmann-Schr��der, 1960) Typosyllis gerlachi Hartmann-Schr��der, 1960: 81, pl.6, figs 43���44, pl. 7, fig. 42. Syllis (Typosyllis) gerlachi.��� Ben���Eliahu 1977: 19, fig. 5. Syllis gerlachi.��� Ba-Akdah et al. 2018: 5, fig. 3. Non Typosyllis gerlachi.��� Campoy 1982: 410, pl. 45. Non Syllis (Typosyllis) gerlachi. ��� Uebelacker 1984: 30���145, fig. 142. Non Typosyllis gerlachi. ��� Licher 1999: 127, pl. 57. Non Syllis gerlachi. ��� San Mart��n 2003: 376, figs 205, 206. Material examined. Soc/ST���95, MAP 95, Shanitan, 12��40.156���N 54��02.850���E, from dead Acropora cf. valida, 8 m, coll. M. Apel 22.03.1999, 1 specimen (SMF 26708). Remarks. Ba-Akdah et al. (2018) redescribed S. gerlachi and provided an overview about the misidentifications of this species in the literature. Habitat. On dead corals. Pioneer on artificial panels (Ba-Akdah et al. 2018). Distribution. Red Sea (Ba-Akdah et al. 2018). First record for Socotra. Type locality. Sarso, Red Sea., Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2020, New species and records of the genus Syllis Savigny in Lamarck, 1818 (Annelida: Syllidae) from Socotra Archipelago (Indian Ocean), pp. 73-88 in Zootaxa 4742 (1) on pages 78-79, DOI: 10.11646/zootaxa.4742.1.4, http://zenodo.org/record/3674479, {"references":["Hartmann-Schroder, G. (1960) Polychaeten aus dem Roten Meer. Kieler Meeresforschungen, 16, 69 - 125.","Ben-Eliahu, N. M. (1977) Polychaete cryptofauna from rims of similar intertidal vermetid reefs on the Mediterranean coast of Israel and in the Gulf of Eilat: Syllinae and Eusyllinae (Polychaeta Errantia: Syllidae). Israel Journal of Zoology, 26, 1 - 58.","Ba-Akdah, M. A., Satheesh, S., Al-Sofyani, A. M. A., Lucas, Y., Alvarez-Campos, P. & San Martin, G. (2018) Taxonomy of some species of the genus Syllis (Annelida: Syllidae: Syllinae) from the Red Sea found among the first colonizers of an artificial substrate. Marine Biological Research, 14 (8), 790 - 805. https: // doi. org / 10.1080 / 17451000.2018.1531133","Campoy, A. (1982) Fauna de Espana. Fauna de Anelidos Poliquetos de la Peninsula Iberica. Serie Biologica. EUNSA (Ediciones de la Universidad de Navarra, S. A.), Pamplona, 781 pp.","Uebelacker, J. M. (1984) Family Syllidae Grube, 1850. In: Uebelacker, J. M. & Johnson, P. G. (Eds.), Taxonomic guide to the polychaetes of the northern Gulf of Mexico. Vol. IV. Mobile, Barry A. Vittor and Associates, Alabama, pp. 1 - 151.","Licher, F. (1999) Revision der Gattung Typosyllis Langerhans, 1879 (Polychaeta: Syllidae). Morphologie, Taxonomie und Phylogenie. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 551, 1 - 336.","San Martin, G. (2003) Annelida Polychaeta II. Syllidae. In: Ramos, M. A. et al. (Eds.), Fauna Iberica. Vol. 21. Museo Nacional de Ciencias Naturales, CSIC, Madrid, pp. 1 - 554."]}

Syllis qamhiyn n.sp. Figures 2���6 urn:lsid:zoobank.org:act: A270D267-0901-4185-80E4-E6D0AAC48A49 Material examined. Holotype (SMF 26713) Soc /ST���726, Ras Qataninh Bay, 12��21.293���N 53��32.659���E, under stones and coral rubble, 8���10 m, coll. T. Wehe 9.4.2000. 1 paratype, same collection data (NHCY 0018); 1 paratype prepared for SEM, Soc/ST���725, Ras Qataninh Bay, dredge, 12��21.789���N 53��31.399���E to 12��21.780���N 53��31.390���E, 18���20 m, coll. T. Wehe 09.04.2000, (SMF 26714, SEM-stub 1311). Diagnosis. Conspicuously thick and short dorsal cirri filled with gelatinous substance; reduced number of compound chaetae from midbody to posterior parapodia, with enlarged shafts and short blades, which become almost unidentate; blades not fused to shafts. Description. Holotype complete specimen, 17.5 mm long, 0.69 mm wide, with 151 chaetigers (Fig. 2A). One incomplete paratype with 134 chaetigers, and other complete, Paratype (SMF 26714), 18.5 mm long, 0,5 mm wide, with 160 chaetigers (Fig. 4B). Body long and slender, filiform, without colour pattern (Figs 2A, B, C; 4B). Prostomium semicircular to oval (Figs 2A; 5A); four small eyes in trapezoidal arrangement. Palps similar in length to prostomium. Median antenna arising between anterior eyes, with 12���13 articles, shorter than combined length of prostomium and palps. Lateral antennae same length as median antenna, with 13 articles each (Fig. 2A). Peristomium dorsally shorter than subsequent segments (Figs. 2A; 5B). Dorsal tentacular cirri about 15���21 articles each; ventral tentacular cirri about 13���14 articles each. Dorsal parapodial cirri relatively thin on anterior segments, alternating relatively long (0.3 mm) and short (0.2 mm); longer cirri similar in length to body width at corresponding chaetiger, with about 17���19 articles, shorter ones about 7���11 articles each (Fig. 2A); from midbody posteriorwards, dorsal cirri shorter than body width, each cirrus thicker in midlength, with about eight well-marked articles, with acute article distally (Fig. 2 A���D); most articles of these dorsal cirri filled with gelatinous substance (Fig. 2D), articles covered by small pores (Fig. 5F). Ventral cirri oval, shorter than parapodial lobes (Figs 2D; 6D). Ventral area of parapodia with almost circular area of pores (Fig. 6 C���E) and internal gland (Fig. 2D). Compound chaetae as heterogomph falcigers; anterior parapodia with about 10 falcigers each; falcigers with slender bidentate blades, proximal tooth distinctly shorter than distal one, and short spines on margin; blades with dorsoventral gradation in length, 42���20 ��m long (Figs 3A; 5C, D). Number of chaetae per parapodium progressively diminishing posteriorly, 4���5 in midbody (Figs 3C; 5E, G, H) and 3���5 on mid-posterior and posterior parapodia (Figs 3E; 6 A���B), shafts becoming larger and blades shorter and minutely bidentate, with proximal tooth much smaller than distal one (Fig. 3E). Midbody falcigers with blades 20���19 ��m long, posterior body falcigers with blades similar, about 19 ��m long. Dorsal and ventral simple chaetae not seen. Anterior parapodia with five slender aciculae each, distally rounded (Fig. 3B), three in midbody parapodia (Fig. 3D); posterior parapodia with two distally oblique aciculae each (Fig. 3F). Pharynx long, extending through about 13 segments (Figs 2A; 4B); pharyngeal tooth elongated, conical, acute, on anterior margin of pharynx (Figs 2A, 4A). Proventricle shorter than pharynx, through 9���10 segments (Fig. 2A), with about 48���50 muscle cell bands. Pygidium small, with two anal cirri, with 7���8 articles each (Fig. 6F). Etymology. The name of the species refers to Dendrosicyos socotrana, the only species of Cucurbitaceae growing into tree form and original from Socotra Island. Its trunk resembles the shape of midbody cirri of S. qamhiyn n.sp. In soqotri language it is named qamhiyn. Remarks. Syllis qamhiyn n.sp. is characterized by having short, thick, distally acute dorsal cirri on midbody and posterior parapodia, and reduced number of falcigers in these parapodia, with enlarged shafts and short, almost unidentate blades, not fused to shafts. Syllis qamhiyn n.sp. belongs to the same group of species of Syllis armillaris (O. F. M��ller, 1771) and related species, the latter considered cosmopolitan but likely a species complex. The mid- and posterior body falcigers of Syllis armillaris also have almost unidentate blades, but they are not so short and the shafts are not as enlarged as in Syllis qamhiyn n.sp. (San Mart��n 2003); furthermore, the mid- and posterior body dorsal cirri of Syllis armillaris are enlarged, but not so much as in Syllis qamhiyn n.sp. Similar differences are between Syllis qamhiyn n.sp. and S. pseudoarmillaris Nogueira & San Mart��n, 2002 from Brazil (Nogueira & San Mart��n 2002); S. pseudoarmillaris has fewer number of articles on midbody dorsal cirri and the compound chaetae of these parapodia are clearly bidentate, with not enlarged shafts; furthermore, the pharynx and proventricle are longer in S. qamhiyn n.sp. Syllis gracilis Grube, 1840, also considered a cosmopolitan species, and S. picta (Kinberg, 1886), from the Indo-Pacific (including the Red Sea), have similar bodies, with enlarged mid- and posterior body dorsal cirri, but in these species at least one of the compound chaetae on these parapodia have fused blade and shaft (San Mart��n 2003; ��lvarez-Campos et al. 2015; 2017). Habitat. Under stones and coral rubble from 8��� 20 m. Distribution. Only known from Socotra Archipelago. Type locality. Ras Qataninh Bay, Socotra Island., Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2020, New species and records of the genus Syllis Savigny in Lamarck, 1818 (Annelida: Syllidae) from Socotra Archipelago (Indian Ocean), pp. 73-88 in Zootaxa 4742 (1) on pages 79-85, DOI: 10.11646/zootaxa.4742.1.4, http://zenodo.org/record/3674479, {"references":["Muller, O. F. (1771) Von den Nereiden. Von Wurmern des sussen und salzigen Wassers. Heineck und Faber, Kopenhagen, 98 pp. [pp. 103 - 200] https: // doi. org / 10.5962 / bhl. title. 14428","San Martin, G. (2003) Annelida Polychaeta II. Syllidae. In: Ramos, M. A. et al. (Eds.), Fauna Iberica. Vol. 21. Museo Nacional de Ciencias Naturales, CSIC, Madrid, pp. 1 - 554.","Nogueira, J. M. & San Martin, G. (2002) Species of Syllis Lamarck, 1818 (Polychaeta: Syllidae) living in corals in the state of Sao Paulo, southeastern Brazil. Beaufortia, 52 (7), 57 - 93.","Grube, E. (1840) Actinien, Echinodermen und Wurmer des Adriatischen- und Mittelmeers nach eigenen Sammlungen beschrieben. Verlag J. H. Bon Konigsberg, 92 pp. https: // doi. org / 10.5962 / bhl. title. 10133","Alvarez-Campos, P., San Martin, G. & Hutchings, P. (2015) The genus Syllis Lamarck, 1818 (Annelida, Syllidae) from Australia. Molecular analysis and re-description of some poorly-known species. Zootaxa, 4052 (2), 297 - 331. https: // doi. org / 10.11646 / zootaxa. 4052.3.2"]}

Syllis lutea (Hartmann-Schr��der, 1960) Typosyllis lutea Hartmann-Schr��der, 1960: 81, pl. 2, fig. 38, pl. 5, figs 39���41; Licher 1999: 177, fig. 79. Typosyllis (Typosyllis) lutea. ��� Hartmann-Schr��der 1979: 89; 1981: 27; 1982: 59; 1991: 29. Syllis (Typosyllis) lutea. ��� Ben-Eliahu 1977: 40. Syllis lutea. ��� Nogueira & San Mart��n 2002: 75, figs 13, 14; San Mart��n et al. 2017: 216, fig. 9. Typosyllis regulata Imajima, 1966: 289, text-fig. 64 a���n. Material examined. Soc/ST���18, MAP 78A, Qualansiyah Bay, 12��41.026���N 53��28.309���E, from dead branched corals, 5���6 m, coll. M. Apel 10.3.1999, 1 specimen (SMF 26711). Habitat. Algae, seaweeds, dead corals, coarse sand, mud. Intertidal to sublittoral (San Mart��n et al. 2017). Distribution. Circumtropical. Red Sea; Japan; Brazil; Cuba; Australia (Queensland; Western Australia) (San Mart��n et al. 2017). New record for Socotra. Type locality. Sarso, Red Sea., Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2020, New species and records of the genus Syllis Savigny in Lamarck, 1818 (Annelida: Syllidae) from Socotra Archipelago (Indian Ocean), pp. 73-88 in Zootaxa 4742 (1) on page 79, DOI: 10.11646/zootaxa.4742.1.4, http://zenodo.org/record/3674479, {"references":["Hartmann-Schroder, G. (1960) Polychaeten aus dem Roten Meer. Kieler Meeresforschungen, 16, 69 - 125.","Licher, F. (1999) Revision der Gattung Typosyllis Langerhans, 1879 (Polychaeta: Syllidae). Morphologie, Taxonomie und Phylogenie. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 551, 1 - 336.","Hartmann-Schroder, G. (1979) Zur Kenntnis des Eulitorals der australischen Kusten unter besonderer Berucksichtigung der Polychaeten und Ostracoden. Teil 2. Die Polychaeten der tropischen Nordwestkuste Australiens (Zwischen Port Samson im Norden und Port Hedland im Suden). Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 76, 75 - 218.","Hartmann-Schroder, G. (1981) Zur Kenntnis des Eulitorals der australischen Kusten unter besonderer Berucksichtigung der Polychaeten und Ostracoden. Teil 6. Die Polychaeten der tropisch-subtropischen Westkuste Australiens (Zwischen Exmouth im Norden und Cervantes im Suden). Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 78, 19 - 96.","Hartmann-Schroder, G. (1982) Zur Kenntnis des Eulitorals der australischen Kusten unter besonderer Berucksichtigung der Polychaeten und Ostracoden. Teil 8. Die Polychaeten der subtropischen-antiborealen Westkuste Australiens (Zwischen Cervantes im Norden und Cape Naturaliste im Suden). Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 79, 51 - 118.","Hartmann-Schroder, G. (1991) Zur Kenntnis des Eulitorals der australischen Kusten unter besonderer Berucksichtigung der Polychaeten und Ostracoden. Teil 16. Die Polychaeten der subtropisch-tropischen bis tropischen Ostkuste Australiens zwischen Maclean (New South Wales) und Gladstone (Queensland) sowie von Heron Island (Grosses Barriere-Riff). Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 88, 17 - 71.","Ben-Eliahu, N. M. (1977) Polychaete cryptofauna from rims of similar intertidal vermetid reefs on the Mediterranean coast of Israel and in the Gulf of Eilat: Syllinae and Eusyllinae (Polychaeta Errantia: Syllidae). Israel Journal of Zoology, 26, 1 - 58.","Nogueira, J. M. & San Martin, G. (2002) Species of Syllis Lamarck, 1818 (Polychaeta: Syllidae) living in corals in the state of Sao Paulo, southeastern Brazil. Beaufortia, 52 (7), 57 - 93.","San Martin, G., Alvarez-Campos, P. & Hutchings, P. (2017) The genus Syllis Savigny in Lamarck, 1818 (Annelida: Syllidae: Syllinae) from Australia (second part): four new species and re-description of twelve previously described species. Zootaxa, 4237 (2), 201 - 243. https: // doi. org / 10.11646 / zootaxa. 4237.2.1","Imajima, M. (1966) The Syllidae (Polychaetous Annelids) from Japan (V). Syllinae (2). Publications of the Seto Marine Biological Laboratory, 14 (4), 253 - 294. https: // doi. org / 10.5134 / 175446"]}

Natural history collections are fundamental for biodiversity research as well as for any applied environment-related research. These collections can be seen as archives of earth´s life providing the basis to address highly relevant scientific questions such as how biodiversity changes in certain environments, either through evolutionary processes in a geological timescale, or by man-made transformation of habitats throughout the last decades and/or centuries. A prominent example is the decline of the European flat oyster Ostrea edulis Linneaus, 1758 in the North Sea and the concomitant invasion of the common limpet slipper Crepidula fornicata, which has been implicated to have negative effects on O. edulis. We used collections to analyse population changes in both species in the North Sea. In order to reconstruct the change in distribution and diversity over the past 200 years, we combined the temporal and spatial information recorded with the collected specimens contained in several European natural history collections. Our data recover the decline of O. edulis in the North Sea from the 19th century to the present and the process of invasion of C. fornicata. Importantly, the decline of O. edulis was nearly completed before C. fornicata appeared in the North Sea, suggesting that the latter had nothing to do with the local extinction of O. edulis in the North Sea.

Eusyllis assimilis Marenzeller, 1875 Eusyllis assimilis Marenzeller, 1875: 158, pl. 3, fig. 2.��� Fauvel, 1923: 294, fig. 112 a���g. San Mart��n, 2003: 114, figs. 52, 53. Eudontosyllis aciculata Knox, 1960: 105, figs. 113���117. Material examined. Socotra, N coast, Southeast of Qualansiyah, 12��40.264���N 53��27.204E, dead coral, 5���6 m, 08.03.1999, 1 specimen (NHCY 007). Socotra, N coast, Shanitan, 600 m off cold store, 12��40.156N 54��02.850E, 8 m, dead Acropora, 22.03.1999, 2 specimens and additional broken posterior piece (SMF 24993). Habitat. Occurring on different kind of substrates (algae, dead corals, sand), from 5 m as in Socotra samples, to more than 500 m depth. (San Mart��n & Hutchings, 2006). Distribution. North Atlantic, Mediterranean Sea, North Pacific, New Zealand, Australia (Western Australia, South Australia, New South Wales) and Arabian Sea. (North West Indian Ocean) (San Mart��n & Hutchings 2006)., Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2019, A new species and nine new records of Syllidae (Annelida) from the Socotra Archipelago (Indian Ocean), pp. 235-258 in Zootaxa 4651 (2) on page 251, DOI: 10.11646/zootaxa.4651.2.2, http://zenodo.org/record/3363175, {"references":["Marenzeller, E. (1875) Zur Kenntnis der adriatischen Anneliden. Zweiter Beitrag. (Polynoinen, Hesioneen, Syllideen). Sitzungsberichte der Akademie der Wissenschaften in Wien. Mathematisch-Naturwissenschaftliche Klasse. Abteilung I: Mineralogie, Biologie, Erdkunde, 72, 129 - 171.","Fauvel, P. (1923) Polychetes Errantes. Faune France, 5, 1 - 488.","San Martin, G. (2003) Annelida, Polychaeta II. Syllidae. In: Ramos, M. A., Alba, J., Belles, X., Gosalbez, J., Guerra, A., Macpherson, E., Martin, F., Serrano, J. & Templado, J. (Eds.), Fauna Iberica. Vol. 21. Museo Nacional de Ciencias Naturales, CSIC, Madrid, pp. 1 - 554.","Knox, G. A. (1960) Biological results of the Chatman Islands 1954 Expedition. Part 3. Polychaeta Errantia. Memoirs of the New Zealand Oceanography Institute, 6, 77 - 143.","San Martin, G. & Hutchings, P. (2006) Eusyllinae (Polychaeta, Syllidae) from Australia with the description of a new genus and fifteen new species. Records of the Australian Museum, 58, 257 - 370. https: // doi. org / 10.3853 / j. 0067 - 1975.58.2006.1466"]}

Eusyllis Malmgren, 1867 Eusyllis Malmgren, 1867: 40. Eudontosyllis Knox, 1960: 105. Type species: Eusyllis blomstrandi Malmgren, 1867., Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2019, A new species and nine new records of Syllidae (Annelida) from the Socotra Archipelago (Indian Ocean), pp. 235-258 in Zootaxa 4651 (2) on page 251, DOI: 10.11646/zootaxa.4651.2.2, http://zenodo.org/record/3363175, {"references":["Malmgren, A. J. (1867) Annulata Polychaeta Spetsbergiae Groenlandiae, Islandiae et Scandinaviae hactenus cognita. Ofversigt af Kongliga Vetenskaps-Akademiens Forhandlingar, 24, 1 - 127. https: // doi. org / 10.5962 / bhl. title. 13358","Knox, G. A. (1960) Biological results of the Chatman Islands 1954 Expedition. Part 3. Polychaeta Errantia. Memoirs of the New Zealand Oceanography Institute, 6, 77 - 143."]}

Megasyllis San Mart��n, Hutchings & Aguado, 2008 Type species: Syllis corruscans Haswell, 1886., Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2019, A new species and nine new records of Syllidae (Annelida) from the Socotra Archipelago (Indian Ocean), pp. 235-258 in Zootaxa 4651 (2) on page 237, DOI: 10.11646/zootaxa.4651.2.2, http://zenodo.org/record/3363175, {"references":["San Martin, G., Hutchings, P. & Aguado, M. T. (2008) Syllinae (Polychaeta, Syllidae) from Australia. Part. 2. Genera Inermosyllis, Megasyllis n. gen., Opisthosyllis, and Trypanosyllis. Zootaxa, 1840 (1), 1 - 53. https: // doi. org / 10.11646 / zootaxa. 1840.1.1","Haswell, W. A. (1886) Observations on some Australian Polychaeta. Proceedings of the Linnean Society of New South Wales, 10, 733 - 756. https: // doi. org / 10.5962 / bhl. part. 17962"]}

Odontosyllis Clapar��de, 1863 Odontosyllis Clapar��de, 1863: 47. San Mart��n, 2003: 101.��� San Mart��n & Hutchings, 2006: 257���370.��� Verdes et al. 2011: 29. Eurymedusa Kinberg, 1865: 61. Parautolytus Ehlers, 1900: 213. Alluaudella Gravier, 1905: 372. Atelesyllis Pruvot, 1930: 39. Pharyngeovalvata Day, 1951: 26. Odontoautolytus Hartmann-Schr��der, 1979: 112. Synpalposyllis Hartmann-Schr��der, 1983: 132. Umbellisyllis Sars, 1869: 254. Type species: Syllis fulgurans Audouin & Milne Edwards, 1833, designated by Hartman, 1959., Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2019, A new species and nine new records of Syllidae (Annelida) from the Socotra Archipelago (Indian Ocean), pp. 235-258 in Zootaxa 4651 (2) on page 250, DOI: 10.11646/zootaxa.4651.2.2, http://zenodo.org/record/3363175, {"references":["Claparede, E. (1863) Beobachtungen uber Anatomie und Entwicklungsgeschichte wirbelloser Thiere an der Kuste von Nor- mandie angestellt. Wilhelm Engelmann, Leipzig, 120 pp. https: // doi. org / 10.5962 / bhl. title. 10030","San Martin, G. (2003) Annelida, Polychaeta II. Syllidae. In: Ramos, M. A., Alba, J., Belles, X., Gosalbez, J., Guerra, A., Macpherson, E., Martin, F., Serrano, J. & Templado, J. (Eds.), Fauna Iberica. Vol. 21. Museo Nacional de Ciencias Naturales, CSIC, Madrid, pp. 1 - 554.","San Martin, G. & Hutchings, P. (2006) Eusyllinae (Polychaeta, Syllidae) from Australia with the description of a new genus and fifteen new species. Records of the Australian Museum, 58, 257 - 370. https: // doi. org / 10.3853 / j. 0067 - 1975.58.2006.1466","Verdes, A. & Pleijel, F. & Aguado, M. T. (2011) A new species of Odontosyllis Claparede, 1863 (Annelida, Syllidae) with re-descriptions of O. liniata Hartmann-Schroder, 1962 and O. gymnocephala Hartmann-Schroder, 1965. Zootaxa, 3095, 27 - 38.","Kinberg, J. G. H. (1865) Annulata nova. Ofversigt af Kongliga Svenska Vetenskaps-Akademiens Forhandlingar, 22, 239 - 258.","Ehlers, E. (1900) Magellanische Anneliden gesammelt wahrend der Schwedischen Expedition nach den Magellanslandern. Festschrift zur Feier des Hundertfunfzigjahrigen Bestehens der Koniglichen Gesellschaft der Wissenschaften zu Gottingen, 1900, 206 - 223.","Gravier, C. (1905) Sur un nouveau Syllidien, Alluaudella nov. gen., madagascariensis nov. sp. Comptes Rendues International Congres de Zoologie de Berne, 6, 372 - 376.","Pruvot, G. (1930) Annelides Polychetes de Nouvelle-Caledonie recueillies par M. Francois, avec une introduction de Pierre Fauvel. Archives de Zoologie Experimentale et Generale, 70, 1 - 94.","Day, J. H. (1951) The polychaete fauna of South Africa. Part 1: The intertidal and estuarine Polychaeta of Natal and Mocambique. Annals of Natal Museum, 12, 1 - 67.","Hartmann-Schroder, G. (1979) Zur Kenntnis des Eulitorals der australischen Kusten unter besonderer Berucksichtigung der Polychaeten und Ostracoden. Teil 2. Die Polychaeten der tropischen Nordwestkuste Australiens (Zwischen Port Samson im Norden und Port Hedland in Suden). Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 76, 75 - 218.","Hartmann-Schroder, G. (1983) Zur Kenntnis des Eulitorals der australischen Kusten unter besonderer Berucksichtigung der Polychaeten und Ostracoden. Teil 9. Die Polychaeten der antiborealen Sudwestkuste Australiens (zwischen Dunsborough im Norden und Denmark im Suden). Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 80, 123 - 167.","Sars, M. (1869) Fortsatte Bemaerkninger over det dyriske Livs Udbredning i Havets Dybder Forhandlingar fra Videnskabs- Selskabet i Kristiania, 1869, 246 - 275. https: // doi. org / 10.5962 / bhl. title. 51281","Audouin, J. V. & Milne Edwards, H. (1833) Classification des Annelides et description de celles qui habitent les cotes de la France. Annales des Sciences Naturelles, Paris, 1, 29, 195 - 269. https: // doi. org / 10.5962 / bhl. part. 8010","Hartman, O. (1959) Catalogue of the polychaetous annelids of the world. Parts I, II (1959), and Supplement (1965). Allan Hancock Foundation Publications, Occasional Papers, 23, 1 - 828."]}

Megasyllis heterosetosa (Hartmann-Schröder, 1991) Figures 1–3 Typosyllis (Typosyllis) heterosetosa Hartmann-Schröder, 1991: 30, figs. 30–35. “ Typosyllis ” heterosetosa (sic) Licher 1999: 298, fig. 115. Megasyllis heterosetosa San Martín et al. 2008: 8–11, figs. 9, 10. Material examined. Socotra, N coast, 12º36.369N 54º19.751E, intertidal, 09.02.1999, 1 specimen (including 4 permanent slides of parapodia) (SMF 24978). Description. Specimen difficult to examine, strongly coiled, hardened and fragile. Body long, broad and strongly built, cylindrical (Fig. 1A), ventrally flattened; about 27 mm long (including stolon), 1.3 mm wide, about 75 segments plus incomplete stolon; yellowish, opaque in alcohol. Prostomium small, short, oval to bilobed, strongly contracted and difficult to observe. Four small orange eyes in trapezoidal arrangement. Antennae shorter than combined length of prostomium and palps; lateral antennae inserted on anterior margin of prostomium, slightly shorter than median antenna; median antenna inserted near posterior margin. Palps large, broad, divergent, basally fused, similar in length to prostomium, ventrally orientated. Peristomium similar in length to subsequent segments; most anterior segments short, sub-divided into 2–3 rings. Median segments inflated, with segmental rings slightly marked (Fig. 1A). Tentacular cirri longer than antennae, dorsal ones slightly shorter than half peristomial width and longer than ventral ones. Antennae, tentacular and dorsal cirri appearing smooth, unarticulated under low magnification; under high magnification irregularly articulated, with indistinct articles (Fig. 2 A–C). Dorsal cirri inserted on cirrophores. Parapodial lobes short, triangular, (Fig. 2 A–C). Ventral cirri digitiform, similar in length or slightly shorter than parapodial lobes (Fig. 2 A–C). Dorsal cirri pseudo-articulated, alternating long cirri, inserted more dorsally (shorter than half of body width) and short cirri, approximately half the length of the long ones, inserted more ventrally; parapodial lobes short, triangular. Compound heterogomph falcigers with subdistal spines, more marked on anterior and dorsal chaetae (Fig. 3A, C); bidentate blades, with short, straight spines on margin, subdistally longer and curved upwards, extending beyond proximal tooth; dorsal and anterior chaetae with both teeth similar, teeth becoming dissimilar progressively along body, more marked on ventral chaetae (Fig. 3A, C); posteriormost ventral compound chaetae with proximal tooth distinctly longer and thicker than distal tooth, with distinctly curved blades and longer subdistal spines. About 14 chaetae anteriorly per parapodium, with elongated blades, progressively reduced to 11 on midbody parapodia (Fig. 3A, C), with dorsoventral gradation in length, changing from anterior (53– 33 μm) (Fig. 3A) to midbody segments (49–42 μm) (Fig. 3C). From midbody backwards, compound chaetae less elongated, with shorter and wider blades, dorso-ventral gradation in length, changing from anterior to posterior, respectively; blades more strongly bidentate, becoming shorter and wider within fascicle ventrally and posteriorly, with proximal tooth becoming larger and more triangular more posterior and ventral (Fig. 3A, C). Dorsal and ventral simple capillary chaetae not seen. Anterior and midbody parapodia with five to six aciculae each, with short, slightly oblique tips (Fig. 3B, D). Pharynx very contracted, about 0.90 mm long, 0.54 mm wide; pharyngeal tooth on anterior margin, surrounded by crown of approximately 10 soft papillae (Fig. 1B). Proventricle, about 2.40 mm long, 1.84 wide, with about 30 muscle cell rows. Reproduction. In members of Megasyllis, sexual reproduction occurs by means of scissiparous schizogamy (San Martín et al. 2014). An incomplete female dicerous stolon was observed attached to the specimen, with approximately 28 segments, yellowish, opaque in alcohol; four orange eyes observed; segments completely filled with yellowish spherical oocytes (Fig. 2C, arrows), about 121 μm in diameter (Fig. 1C), nucleus can be observed (Fig. 1C, arrow). Cirri from stolon thinner and shorter than those of stock. Habitat. Coralline and muddy sand, seagrasses; intertidal to shallow depths (San Martín et al., 2008). Distribution. Originally described from Queensland (Australia) (Hartmann-Schröder, 1991); San Martín et al. (2008) recorded this species also in New South Wales (Australia). First record from the Indian Ocean., Published as part of Rodríguez, Yolanda Lucas, Martín, Guillermo San & Fiege, Dieter, 2019, A new species and nine new records of Syllidae (Annelida) from the Socotra Archipelago (Indian Ocean), pp. 235-258 in Zootaxa 4651 (2) on pages 237-241, DOI: 10.11646/zootaxa.4651.2.2, http://zenodo.org/record/3363175, {"references":["Hartmann-Schroder, G. (1991) Zur Kenntnis des Eulitorals der australischen Kusten unter besonderer Berucksichtigung der Polychaeten und Ostracoden. Teil 16. Die Polychaeten der subtropisch-tropischen bis tropischen Ostkuste Australiens zwischen Maclean (New South Wales) und Gladstone (Queensland) sowie von Heron Island (Groβes Barriere-Riff). Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 88, 17 - 71.","Licher, F. (1999) Revision der Gattung Typosyllis Langerhans, 1879 (Polychaeta: Syllidae). Morphologie, Taxonomie und Phylogenie. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 551, 1 - 336.","San Martin, G., Hutchings, P. & Aguado, M. T. (2008) Syllinae (Polychaeta, Syllidae) from Australia. Part. 2. Genera Inermosyllis, Megasyllis n. gen., Opisthosyllis, and Trypanosyllis. Zootaxa, 1840 (1), 1 - 53. https: // doi. org / 10.11646 / zootaxa. 1840.1.1","San Martin, G., Aguado, M. T. & Alvarez-Campos, P. (2014): Revision of the genus Megasyllis (Annelida, Syllidae) with descriptions of four new species. Journal of the Marine Biological Association of the UK, 94 (2), 331 - 351."]}

Opisthosyllis Langerhans, 1879 Opisthosyllis Langerhans, 1879: 541. Type species: Opisthosyllis brunnea Langerhans, 1879., Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2019, A new species and nine new records of Syllidae (Annelida) from the Socotra Archipelago (Indian Ocean), pp. 235-258 in Zootaxa 4651 (2) on page 241, DOI: 10.11646/zootaxa.4651.2.2, http://zenodo.org/record/3363175, {"references":["Langerhans, P. (1879) Die Wurmfauna von Madeira. Zeitschrift fur Wissenschaftliche Zoologie, 33, 513 - 592. https: // doi. org / 10.5962 / bhl. title. 63986"]}

Haplosyllis djiboutiensis Gravier, 1900 Syllis (Haplosyllis) djiboutiensis Gravier 1900: 147���149, pl. 9, fig. 3. Haplosyllis djiboutiensis Lattig & Mart��n 2009: 18, fig. 12.��� Lattig et al. 2010: 10���14, figs. 6, 7.��� Lattig & Martin 2011: figs. 1A���F; 2A, B. Haplosyllis spongicola Imajima 1966 a: 220���221, text-figs. a���h.��� Lee & Rho 1994: 132���134, fig. 1, a���f. Material examined. Socotra, S coast, Steroh, Nogid, 12��19.006N 53��52.845E, 13���15 m, rocky, 14.03.1999, 1 specimen (SMF 24974). Socotra, Qualansiyah Bay, 12��41.026N 53�� 28.309E, 5-6 m, 10.03.1999, 1 specimen (SMF 24975). Socotra, Rhiy di Hamri, 12��40.429N 54��11.731E, 7���9 m, 19.03.1999, 1 specimen, (NHCY 002). Socotra Archipelago, Kal Farun rock outcrop, 12��26.049N 52��08.07E, 9.5���12.5 m, 03.04.2000, 1 specimen (SMF 24977). Habitat. Lattig & Mart��n (2011) recorded high densities of specimens associated with undetermined sponges in Qatar and Abu Dhabi (Persian Gulf). The Socotra Archipelago specimens were found in different types of substrate, including sand, hard substrate, macro algae, turf algae, hard coral, and soft coral. Distribution. Red Sea, Korea, Japan, Australia (Western Australia, South Australia, New South Wales, Northern Territory) (Lattig et al. 2010), Persian Gulf., Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2019, A new species and nine new records of Syllidae (Annelida) from the Socotra Archipelago (Indian Ocean), pp. 235-258 in Zootaxa 4651 (2) on page 237, DOI: 10.11646/zootaxa.4651.2.2, http://zenodo.org/record/3363175, {"references":["Gravier, C. (1900) Contribution a l'etude des Annelides Polychetes de la Mer Rouge. Premiere partie. Nouvelles Archives du Museum d'Histoire Naturelle, Paris, 2, 137 - 282.","Lattig, P. & Martin, D. (2009) A Taxonomic Revision of the Genus Haplosyllis Langerhans, 1887 (Polychaeta: Syllidae: Syllinae). Zootaxa, 2220, 1 - 40.","Lattig, P., Martin, D. & San Martin, G. (2010) Syllinae (Syllidae: Polychaeta) from Australia. Part 4. The genus Haplosyllis Langerhans, 1879 (Polychaeta: Syllidae: Syllinae). Zootaxa, 2552, 1 - 36. https: // doi. org / 10.11646 / zootaxa. 2552.1.1","Lattig, P. & Martin, D. (2011) Two new endosymbiotic species of Haplosyllis (Polychaeta: Syllidae) from the Indian Ocean and Red Sea, with new data on H. djiboutiensis from the Persian Gulf. Italian Journal of Zoology, 78, 112 - 23. https: // doi. org / 10.1080 / 11250003.2011.569373","Imajima, M. (1966 a) The Syllidae (Polychaetous Annelids) from Japan (II). Autolytinae. Publications of the Seto Marine Biological Laboratory, 14, 27 - 83. https: // doi. org / 10.5134 / 175422","Lee, J. W. & Rho, B. J. (1994) Systematic studies on Syllidae (Annelida, Polychaeta) from the South Sea and the East Sea in Korea. Korean Journal of Systematic Zoology, 10, 131 - 144."]}

Salvatoria koorineclavata San Mart��n, 2005 Brania clavata Hartmann-Schr��der, 1979: 100, figs. 129���133; 1980: 53; 1990: 53; 1991: 37. Not Clapar��de, 1863. Salvatoria koorineclavata San Mart��n 2005, figs. 11A���G, 12A���E.��� Ding & Westheide 2008:128���131, fig. 3. Material examined. Socotra, N coast, Southeast of Qualansiyah, 12��40.264���N 53��27.204E, from dead coral, 6 m, 08.03.1999, 1 specimen (SMF 24994). Habitat. Common in shallow waters on a variety of substrates to 29 m depth (San Mart��n, 2005). In Socotra in shallow waters among dead corals. Distribution. Australia (all states) (San Mart��n, 2005)., Published as part of Rodr��guez, Yolanda Lucas, Mart��n, Guillermo San & Fiege, Dieter, 2019, A new species and nine new records of Syllidae (Annelida) from the Socotra Archipelago (Indian Ocean), pp. 235-258 in Zootaxa 4651 (2) on page 253, DOI: 10.11646/zootaxa.4651.2.2, http://zenodo.org/record/3363175, {"references":["San Martin, G. (2005) Exogoninae (Polychaeta: Syllidae) from Australia with the description of a new genus and twenty-two new species. Records of the Australian Museum, 57, 39 - 152. https: // doi. org / 10.3853 / j. 0067 - 1975.57.2005.1438","Hartmann-Schroder, G. (1979) Zur Kenntnis des Eulitorals der australischen Kusten unter besonderer Berucksichtigung der Polychaeten und Ostracoden. Teil 2. Die Polychaeten der tropischen Nordwestkuste Australiens (Zwischen Port Samson im Norden und Port Hedland in Suden). Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 76, 75 - 218.","Claparede, E. (1863) Beobachtungen uber Anatomie und Entwicklungsgeschichte wirbelloser Thiere an der Kuste von Nor- mandie angestellt. Wilhelm Engelmann, Leipzig, 120 pp. https: // doi. org / 10.5962 / bhl. title. 10030","Ding, Z. & Westheide, W. (2008) Interstitial Exogoninae from the Chinese coast (Polychaeta, Syllidae). Senckenbergiana biologica, 88, 125 - 159."]}

Trypanosyllis mercedesae n. sp. Figures 4–7 urn:lsid:zoobank.org:act: 99769D77-6407-4F13-84F0-91E4045B875F Material examined. Socotra Archipelago, 12º26.049N 52º08.07E, Kal Farun rock outcrop, 9.5-12.5 m, 03.04.2000. Holotype (including 3 permanent slides with parapodia) (SMF 24983) and one paratype (including 1 permanent slide of a parapodium) (NHCY 005). Diagnosis. Body long, distinctly flattened, with pigmented dorsal cirri, two thin, clearly marked, red-garnet dorsal bands on each anterior segment, up to the proventricular level, relatively short and thick, pigmented dorsal cirri, and almost triangular teeth on the trepan. Description. Holotype longest and complete specimen, 44 mm long, 1.25 mm wide, 281 chaetigers (Fig. 4A); paratype incomplete, without pygidium, 7.8 mm long, 1.28 mm wide, 69 chaetigers. Antennae and tentacular cirri white-yellowish (Fig. 4A, B); dorsal cirri pigmented in garnet or red-wine. Body markedly dorso-ventrally flattened, ribbon-like, and tapered posteriorly. Dorsum of each anterior segment with two transverse red-garnet lines (Fig. 4 A–B,) disappearing progressively some segments after proventricle. Prostomium oval, wider than long, posteriorly bilobed with a conspicuous cleft; two pairs of garnet coloured eyes, in open trapezoidal arrangement; anterior pair larger than posterior one. One pair of palps slightly shorter than prostomium, completely separated, kidney-shaped. Median antenna inserted frontally, near anterior margin of prostomium, with 23–24 articles. Lateral antennae shorter, with 20 articles, emerging slightly behind median antenna. Tentacular segment small, reduced dorsally, with two pairs of tentacular cirri. Dorsal tentacular cirri with 23 articles, ventral ones with 13–15 articles. Dorsal cirri alternating in length; longest cirri slightly longer than body width. First long dorsal cirri about 32–34 articles next ones 27–30 articles; anterior short dorsal cirri about 17–19 articles. Midbody long dorsal cirri with 22–25 articles; midbody short dorsal cirri 11–19. Posterior long dorsal cirri with 23–25 articles; short ones 13–16. Ventral cirri digitiform, shorter than parapodial lobes (Fig. 5 A–C). Anterior parapodia with about 12–13 compound chaetae, with falcigerous blades, bidentate, short spines along margin (Fig. 6A); gradation in length of blades 48 μm long above, 38 μm below. Number and shape of chaetae varying gradually from anterior to posterior parapodia. Midbody parapodia with 6–7 falcigers each, 44 μm above 28 μm below (Fig. 6C), bidentate, proximal tooth small, acute (Fig. 6C), distal tooth larger and also pointed; interspace between distal and proximal tooth wide; proximal part of the blade with small spines on edge; most dorsal ones somewhat elongated and more similar to those of anterior parapodia, with both teeth similar and short spines along edge. Posterior parapodia with similar falcigers as midbody, six per parapodium, 38 μm above (Fig. 6E), 26 μm below. Anterior parapodia with four aciculae each of different sizes, one of them slightly oblique at tip (Fig. 6B); from midbody parapodia, three straight acicula per parapodium, one of them distinctly smaller than other ones (Fig. 6D); posterior aciculae also straight and slightly pointed (Fig. 6F), two per parapodium, one of them smaller. Pharynx brownish, in holotype across approximately 12 segments; proventricle through 16 segments. Pharynx and proventricle of paratype dissected (Fig. 7B); pharynx brownish, through 16 segments, slightly contracted, 1.28 mm long, 0.42 mm surrounded on anterior margin by a crown of 8 finger-shaped papillae (Fig. 7A); trepan with 9–10 brownish triangular teeth (Fig. 7C); proventricle through 13–16 segments (Fig. 7B), 2.1 mm long, 0.57 mm wide, with about 29 muscle cell rows. Pygidium in process of regeneration. Remarks Trypanosyllis mercedesae n. sp. is characterized by having a long body, distinctly flattened, with dorsal cirri pigmented in garnet or red-wine, two slender but clearly marked reddish bands on each anterior segment, up to the proventricular level, relatively short and thick pigmented dorsal cirri, and short almost triangular teeth on trepan. Trypanosyllis richardi is similar and lives in the nearby area of the Red Sea; however, that species has distinctly longer and slender dorsal cirri, which are unpigmented, the two reddish bands on the dorsum of anterior segments are larger, appearing almost as a single, broad band, also present posteriorly to proventricle, and the pharyngeal teeth are longer, not so acute as those of T. mercedesae n. sp. According to WORMS (2019) and Álvarez-Campos et al. (2017, 2018), the genus Trypanosyllis currently consists of about 40 valid species (excluding the species transferred to Trypanedenta Imajima & Hartman, 1964; Trypanoseta Imajima & Hartman, 1964 and Pseudosyllis Grube, 1863). Álvarez-Campos et al. (2017, 2018) revised this genus, and described or re-described numerous species. There are many species of Trypanosyllis with a similar colour pattern, formed by two reddish dorsal bands per segment, at least on anterior segments. Most of the species have both bands slender or one slender and the other larger. Only T. luzonensis (Pillai, 1965), from Philippines, China and Australia, has a similar pattern of pigmentation than T. mercedesae, n. sp., formed by two large bands per segment, appearing to be a single band. However, T. luzonensis has the two bands more marked (sometimes almost fused to each other) and larger than those of T. mercedesae n. sp. and they continue almost to the posterior part of body, while disappearing after the proventricle in T. mercedesae n. sp., the dorsal cirri are long and lacking pigmentation, being much shorter, thicker and pigmented in T. mercedesae n. sp. The compound chaetae in both species are similar, but relatively shorter and less elongated in T. luzonensis. Trypanosyllis krohnii, from W Mediterranean, has a similar colour pattern, but it is proportionally wider, with shorter, unpigmented dorsal cirri, and the compound chaetae are more markedly bidentate (see the re-description in Álvarez-Campos et al. 2017). Habitat. In dead corals at shallow bottoms (9.5 to 12.5 m). Distribution. Only known in Kal Farun rock outcrop, Socotra Archipelago. Etymology. Named after Mª de las Mercedes Rodríguez del Olmo, beloved mother of YLR., Published as part of Rodríguez, Yolanda Lucas, Martín, Guillermo San & Fiege, Dieter, 2019, A new species and nine new records of Syllidae (Annelida) from the Socotra Archipelago (Indian Ocean), pp. 235-258 in Zootaxa 4651 (2) on pages 242-247, DOI: 10.11646/zootaxa.4651.2.2, http://zenodo.org/record/3363175, {"references":["Alvarez-Campos, P., Giribet, G., San Martin, G., Rouse, G. W. & Riesgo, A. (2017) Straightening the striped chaos: systematics and evolution of Trypanosyllis and the case of its pseudo-cryptic type species Trypanosyllis krohnii (Annelida, Syllidae). Zoological Journal of the Linnean Society, 179, 492 - 540. https: // doi. org / 10.1111 / zoj. 12443","Imajima, M. & Hartman, O. (1964) The polychaetous annelids of Japan. Allan Hancock Foundation Occasional Papers, 26, 1 - 452.","Pillai, T. G. (1965) Annelida Polychaeta from the Philippines and Indonesia. Ceylon Journal of Science, 5 (2), 109 - 177."]}

Myrianida pachycera (Augener, 1913) Autolytus pachycerus Augener, 1913: 257–260, pl. 2, fig. 11, 12, text-fig. 40A–C; 1927: 157–158.— Nygren & Sundberg 2003: GenBank sequences, 16S rDNA partial sequence AF474258, and 18S rDNA partial sequence AF474304. Myrianida pachycera Imajima 1966b: 79–82, fig. 26A–L.— Imajima 1967: 417. Myrianida pachycerus Hartman 1966: 362–363, fig. 1A–B. Autolytus purpureimaculata Okada 1933: 332–338, figs. 6–11; 1937.— Imajima & Hartman 1964: 100. Myrianida crassicirrata Hartmann-Schröder, 1965: 119–121, figs. 47–49. Material examined. Socotra, Samhah Island, intertidal, amongst algae, 12º10’99N / 53º04’23E, algae, 07.04.2000, 1 specimen (SMF 24995). Remarks. One female specimen with 28 segments up to beginning of the stolons, 3.8 mm long, 0.64 mm wide, yellowish coloration, cirri with same length along the body up to formation of stolon. A line of five stolons attached in different stages of maturation. Specimen very fragile. Four red eyes arranged in open trapezoidal arrangement. Nuchal epaulettes not visible. Palps fused along all their length. No ciliation observed in dorsal view. Median antenna thick, flat reaching almost chaetiger 10. Lateral antennae and ventral tentacular cirri 1/2 length of median antenna. Lateral antennae and tentacular cirri cylindrical, annulated. Almost all cirri lost on left side. First dorsal cirri similar in length to lateral antennae. Second dorsal cirri ¾ length of median antenna, thick and flat. Cirri 3 to 8 alternate in length short/long and in thick/flat shape. Schizogamous reproduction by gemmiparity, behind either chaetiger 31 or 34 (Nygren, 2004). Habitat. Intertidal, shallow depths, together with rich epifauna (Nygren, 2004); in Socotra also amongst algae. Distribution. East Indian Ocean, Pacific, West Atlantic. Australia, Japan, Hawaii, California, Florida (Nygren, 2004)., Published as part of Rodríguez, Yolanda Lucas, Martín, Guillermo San & Fiege, Dieter, 2019, A new species and nine new records of Syllidae (Annelida) from the Socotra Archipelago (Indian Ocean), pp. 235-258 in Zootaxa 4651 (2) on pages 253-254, DOI: 10.11646/zootaxa.4651.2.2, http://zenodo.org/record/3363175, {"references":["Augener, H. (1913) Polychaeta I, Errantia. Die Fauna Sudwest-Australiens. Ergebnisse der Hamburger sudwest-australischen Forschungreise, 4 (5), 65 - 304. [1905]","Nygren, A. & Sundberg, P. (2003) Phylogeny and evolution of reproductive modes in Autolytinae (Syllidae, Annelida). MolecularPhylogeny and Evolution, 29, 235 - 249. https: // doi. org / 10.1016 / S 1055 - 7903 (03) 00095 - 2","Imajima, M. (1966 b) The Syllidae (Polychaetous Annelids) from Japan (IV). Syllinae (1). Publications of the Seto Marine Biological Laboratory, 14, 219 - 252. https: // doi. org / 10.5134 / 175436","Imajima, M. (1967) Errant polychaetous annelids from Tsukumo Bay and vicinity of Noto Peninsula, Japan. Bulletin of the National Science Museum Tokyo, 10, 403 - 441.","Hartman, O. (1966) Polychaetous annelids of the Hawaiian Islands. Occasional Papers of the Bernice P. Bishop Museum, 23, 163 - 252.","Okada, Y. K. (1933) Two interesting syllids, with remarks on their asexual reproduction. Memoires of the College of Science, Kyoto Imperial University, Series B, 8, 325 - 339.","Imajima, M. & Hartman, O. (1964) The polychaetous annelids of Japan. Allan Hancock Foundation Occasional Papers, 26, 1 - 452.","Hartmann-Schroder, G. (1965) Zur Kenntnis der eulitoralen Polychaetenfauna von Hawaii, Palmyra und Samoa. Abhandlungen und Verhandlungen des Naturwissensschaftlichen Vereins in Hamburg, Supplement 9, 81 - 161.","Nygren, A. (2004) Revision of Autolytinae (Syllidae: Polychaeta). Zootaxa, 680 (1), 1 - 314. https: // doi. org / 10.11646 / zootaxa. 680.1.1"]}