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Anguillosyllis sp. (Figure 9g –j) Material examined. St. 16: 1 individual. Description. Specimen complete, 2 mm long and 0.17 mm wide for 14 chaetigers (Fig. 9g). Prostomium ovate, broader than long, difficultly distinguishable from palps; palps distally acute, completely fused, without traces of longitudinal furrow. Eyes absent, lateral antennae short, papilliform; median antenna almost as long as the prostomium, digitiform, backwards directed. One pair of very long, thin cirri on peristomium. Segments becoming wider towards posterior part of body. Parapodia rectangular, elongated, dorsal cirri not seen, with 6–9 long chaetae. Dorsal simple chaeta very long and thin, with rounded tip and a well-developed subdistal spine (Fig. 9h); compound chaetae with smooth shafts, strong dorso-ventral gradation in the size of blades, from approximately 80 µm most dorsal to 12 µm most ventral. All blades unidentate, with smooth edge and blunt tip, longer blades slightly sinuous, shorter blades straight (Fig. 9i). One robust acicula, with briskly crooked tip, forming a ca. 90° angle (Fig. 9j). Pygidium rounded, wide, anal cirri not seen. Pharynx and proventricle difficult to distinguish; pharynx narrow, through three segments, without pharyngeal tooth; proventricle barrel-shaped, through two chaetigers, with 12–15 muscle cell rows. Distribution. Sardinian Slope, at 2100 m depth. Remarks. The low number of body segments, along with the pharynx without tooth, the small size of antennae and the completely fused palps allow to assign the examined individual to the genus Anguillosyllis Day, 1963 (Aguado & San Martín 2008). The morphology of the examined specimen, however, does not correspond to any of the four known species of Anguillosyllis. The entirely fused palps resemble those in A. lanai Barroso, Paiva, Nogueira & Fukuda, 2017 and A. pupa (Hartman, 1965), while the shape of antennae and the number of proventricle cell rows resemble those of A. lanai (Barroso et al. 2017). However, it differs from the latter in having the blades of compound chaetae up to 80 µm long (up to 170 µm in A. lanai), up to 8 compound chaetae (up to 15 in A. lanai) and the parapodial glands absent (present in A. lanai). Our specimen shows 14 chaetigers (10 or 11 in all known Anguillosyllis species), thin elongate tentacular cirri (papilliform in the other species) and a crooked acicula (unknown in the other species). Overall, our specimen seems to belong to an undescribed species. However, we consider our single individual in poor preservation status (most appendages are lacking) as not enough to formally describe it as a new species. Nonetheless, it represents the first Mediterranean record of the genus.

Exogone lopezi San Martín, Ceberio & Aguirrezabalaga, 1996 Exogone lopezi San Martín et al. 1996: 37: 255, Fig. 6; San Martín 2003: 259 ‒262, Figs 140‒141. Material examined. St. 2: 1 individual; St. 11: 1 individual; St. 12: 5 individuals; St. 13: 1 individual. Distribution. Eastern Atlantic Ocean (San Martín et al. 1996); Aegean Sea (Simboura & Zenetos 2005); Adriatic Sea (present data) and Sea of Sardinia (present data), Western Mediterranean. Remarks. The examined individuals perfectly correspond to the original description (San Martín et al., 1996). This is the first occurrence of this species in Italian waters.

Syllis sp. 1 (Figure 8) Langerhansia caeca Katzmann 1973: 439 ���442, Fig. 3; Arvanitidis 2000: 77. Typosyllis caeca Licher 1999: 64 ���66, Fig. 29. Syllis katzmanni Arvanitidis 1994: 98 ���100. Material examined: St. 3: 1 individual; St. 6: 1 individual; St. 11: 5 individuals; St. 12: 2 individuals. Description. All individuals incomplete; best preserved individual 48 chaetigers for ca. 8 mm total length, 0.37 mm maximum width (Fig. 8a). Body thin, slender, elongate; prostomium ovate, distinctly wider than long, without eyes, palps elongate, distally rounded, longer than prostomium. Antennae, peristomial cirri and dorsal cirri moniliform, articulated, similar in shape, easily brokable; median antenna with more than 20 articles, lateral antennae with 10���15 articles, peristomial cirri and first dorsal cirri with up to 15 articles, then becoming shorter (7��� 9). Parapodia well-developed, with two aciculae of similar shape, pointed, subdistally slightly enlarged; in anterior parapodia both aciculae similar in size; in midbody parapodia one acicula distinctly larger than other; in posterior parapodia single acicula, with slightly enlarged subdistal region and rounded tip. Up to 10 compound chaetae with smooth, heterogomph shafts: 1���2 long spiniger-like chaetae, with extremely long blade (80���100 ��m), unidentate, with almost smooth margin (Fig. 8b); 1���3 shorter spiniger-like chaetae, with shorter blades (40���50 ��m), finely bidentate, with almost smooth ventral edge (Fig. 8c); and 4���5 falcigers, with shorter blade (35���17 ��m), bidentate, with finely serrated edge and slightly rounded tip (Fig. 8d). Simple capillary chaetae apparently absent. Pharynx through 6 chaetigers, relatively broad, with small, pointed tooth; proventricle through 7 chaetigers, with 31���34 muscle cell rows. Distribution. Adriatic Sea (Katzmann 1973), Aegean Sea (Arvanitidis 2000), Levant Sea (��inar & Ergen 2003), Sicily Channel and Sea of Sardinia; from deep circalittoral (140 m depth) of the Adriatic Sea (Katzmann 1973 Cantone & Di Pietro, 2002) to bathyal (500 and 1000 m depth with compact, clayish muds) bottoms (Arvanitidis 2000; ��inar & Ergen 2003). Records of this species (as Syllis caeca / Langerhansia caeca) from sciaphilous hard bottoms habitats at distinctly lower depths (10���45 m) (Campoy 1982; Rubbiani 1986; Sard�� 1991) most likely refer to a different species. Remarks. The morphology of the examined individuals agrees with that of the type material of Langerhansia caeca Katzmann, 1973 redescribed by Licher (1999) as Typosyllis caeca, even if secondary teeth in falciger chaetae are often difficult to see at 400x magnification. The only remarkable difference is the less pronounced spinulation along the ventral edge of spiniger chaetae. This species was described as Langerhansia caeca by Katzmann (1973) for the central Adriatic Sea. Langerhansia Czerniavsky, 1881 is currently a synonymy of Syllis Lamarck, 1818. However, the name is preoccupied by Syllis caeca Monro, 1933. Hence, the species was renamed as Syllis katzmanni Katzmann, 1973 by Arvanitidis (1994). Later, Licher (1999), placed Langerhansia caeca in Typosyllis, thus resurrecting Typosyllis caeca (with T. katzmanni as synonymy). Since Licher���s use of Typosyllis is not widely accepted (San Mart��n 2003), and the taxonomy of Syllis is currently unclear (Aguado et al. 2012), Katzmann���s original name (L. caeca) in the current combination would be unavailable. However, according to ICZN rules (ICZN code, art. 8) Arvanitidis��� name (S. katzmanni) is not valid, as the dissertation where it was provided has not been published. Our data confirm the bathymetric range, as well as the peculiar ecological requirements of this species, which appears to be the deepest Syllinae species occurring in the Mediterranean Sea., Published as part of Langeneck, Joachim, Musco, Luigi, Busoni, Giulio, Conese, Ilaria, Aliani, Stefano & Castelli, Alberto, 2018, Syllidae (Annelida: Phyllodocida) from the deep Mediterranean Sea, with the description of three new species, pp. 197-220 in Zootaxa 4369 (2) on pages 211-212, DOI: 10.11646/zootaxa.4369.2.3, http://zenodo.org/record/1135678, {"references":["Katzmann, W. (1973) Polychaeten von Sedimentboden der mittleren Adria (50 - 525 m). Zoologische Jahrbucher, Abteilung fur Systematik, Okologie und Geographie der Tiere, 100, 436 - 450.","Arvanitidis, C. (2000) Polychaete fauna of the Aegean Sea: inventory and new information. Bulletin of Marine Science, 60, 73 - 96.","Licher, F. (1999) Revision der Gattung Typosyllis Langerhans, 1879 (Polychaeta: Syllidae). Morphologie, Taxonomie und Phylogenie. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 551, 1 - 336.","Arvanitidis, C. (1994) Systematic and bionomic study of the macrobenthic Polychaete (Annelida) of the Northern Aegean. Ph. D. Thesis, Aristotle University of Thessaloniki, Thessaloniki, 512 pp., annex. [in Greek]","Cantone, G. & Di Pietro, N. (2002) Policheti bentonici della Fossa di Pomo (Medio Adriatico). Biologia Marina Mediterranea, 9, 494 - 500.","Campoy, A. (1982) Fauna de Espana. Fauna de Anelidos poliquetos de la Peninsula Iberica. Publicaciones de la Universidad de Navarra, Serie Zoologica, 7, 1 - 400.","Rubbiani, C. (1986) Distribuzione dei policheti di substrato duro su una parete verticale situata lungo le coste dell'isola di Capraia (arcipelago toscano). Unpublished master thesis, University of Modena, Modena, 86 pp.","Lamarck, J. B. de (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; precedes d'une Introduction offrant la determination des caracteres essentiels de l`Animal, sa distinction du vegetal et desautres corps naturels, enfin, l'Exposition des Principes fondamentaux de la Zoologie. Vol. 5. Deterville, Paris, 612 pp.","Monro, C. C. C. A. (1933) The Polychaeta Errantia collected by Dr. C. Crossland at Colon, in the Panama region, and the Galapagos Islands during the Expedition of the S. Y. ' St. George'. Proceedings of the Zoological Society of London, 103, 1 - 96. https: // doi. org / 10.1111 / j. 1096 - 3642.1933. tb 01578. x","San Martin, G. (2003) Anelidos Poliquetos. Familia Syllidae Grube, 1850. Museo Nacional de Ciencias Naturales, CSIC, Madrid, 554 pp.","Aguado, M. T., San Martin, G. & Siddall, M. E. (2012) Systematics and evolution of syllids (Annelida, Syllidae). Cladistics, 28, 234 - 250. https: // doi. org / 10.1111 / j. 1096 - 0031.2011.00377. x"]}

Exogone sophiae Langeneck, Musco & Castelli n. sp. (Figures 3���4) Material examined. Holotype (MSNP: P/3879): St. 8, Northern Tyrrhenian Sea, 110 m. Paratypes: St. 8: 1 individual (MSNP: P/001/SEM); St. 10: 2 individuals (MSNP: P/242/V; P/246/V). Additional material: St. 8: 1 individual. Description. Holotype complete specimen, 6 mm long for 47 chaetigers, 0.30 mm wide. All paratypes incomplete. Prostomium short, rectangular, distinctly broader than long, with four rounded, small eyes in trapezoidal arrangement, reddish, sometimes difficult to distinguish in preserved material. Antennae absent in all examined individuals (Fig. 4a). Palps long, broad, fused for their total length, with barely noticeable distal notch. Dorsal cirri very small, oval, slightly longer in the posterior region, lacking at chaetiger 2 (Fig. 3a). First four parapodia with 2 compound spiniger-like chaetae and 3���4 falcigers, after chaetiger 5 only 1 spiniger-like and 3 falcigers (Fig. 4c). Anterior spiniger-like compound chaetae with thick, distally spinulous shaft (Figs 3c, 4d), and thin, elongated blades 25���35 ��m long; blades sometimes slightly curved with several long teeth on basal part (Figs 3c, 4d), difficult to see with the light microscope. Posterior spinigers-like chaetae similar but shorter and thinner, 15���20 ��m long blades. Anterior falcigers with 7.5���10 ��m long blade, with very small distal tooth, massive, strong proximal tooth, and relatively short, coarse serration along ventral edge (Figs 3d, 4e). Posterior falcigers shorter, blades 3.8���5 ��m long, with thicker basal part. Anterior dorsal simple chaetae unidentate, smooth; posterior dorsal simple chaetae become distinctly thicker, with a subdistal notch (Fig. 3e). Ventral simple chaetae absent. Pharynx long, relatively wide, extending through six chaetigers, with a large, triangular distal tooth. Proventricle barrelshaped, as long as pharynx, with 20���23 muscle cell rows. Pygidium sub-triangular with two very long, tapering anal cirri (Fig. 3b). Etymology. This species is dedicated to Sophie Langeneck, sister of the first author. Distribution. Tyrrhenian Sea, at a depth between 100 and 110 m. Remarks. Exogone sophiae n. sp. is chiefly characterised by the absence of antennae; albeit preservation may cause the loss of antennae in some syllid species, we believe that this character is not a preservation artefact, as all the sampled individuals do not show any trace of antennae, nor of scars indicating the lost of antennae. Moreover, dorsal cirri are perfectly preserved, suggesting that preservation should not have altered the soft appendages of the collected specimens. Until now two species of Exogone without prostomial antennae have been described, namely Exogone acerata San Mart��n & Parapar, 1990, and Exogone oculata (Hartman & Fauchald, 1971) (San Mart��n, 1991). E. sophiae differs from E. acerata in the absence of dorsal cirri at chaetiger 2 (present in E. acerata), in the less pronounced spinulation on shafts of spiniger-like chaetae and in the longer spines on blades of spiniger-like chaetae (San Mart��n & Parapar, 1990). Exogone sophiae appears closer to E. oculata, as both species lack the dorsal cirrus at chaetiger 2, but E. oculata lacks spiniger-like chaetae on the first four chaetigers. Moreover, both species are provided of ventral simple chaetae, that are absent in all examined individuals of the new species. Among Mediterranean species, E. sophiae appears particularly close to Exogone verugera (Clapar��de, 1868) and Exogone dispar (Webster, 1879) in size and overall body shape and number of proventricle cell rows. Apart from the absence of antennae, this species differs from E. verugera as E. sophiae has smaller, non-coalescent eyes, longer blades of falciger chaetae, with a higher number of marginal teeth, and slightly shorter blades of spinigerlike chaetae with a more pronounced spinulation along the ventral edge; moreover E. sophiae lacks ventral simple chaetae. Exogone dispar has similar blades of falciger chaetae, and a more pronounced spinulation along the ventral edge of spiniger-like blades (San Mart��n, 2003); however, in E. sophiae such spinulation is even more pronounced (Fig. 3d). Moreover, E. dispar has dorsal cirri at the second chaetiger. Lastly, E. sophiae might resemble Exogone lopezi San Mart��n, Ceberio & Aguirrezabalaga, 1996, since this last species apparently lacks ventral simple chaetae, and has very small antennae that are difficult to see. However, E. lopezi has falciger chaetae with long, thread-like marginal teeth that outgrow the chaetal tip, whereas in E. sophiae the marginal serration of falcigers is coarser and less developed., Published as part of Langeneck, Joachim, Musco, Luigi, Busoni, Giulio, Conese, Ilaria, Aliani, Stefano & Castelli, Alberto, 2018, Syllidae (Annelida: Phyllodocida) from the deep Mediterranean Sea, with the description of three new species, pp. 197-220 in Zootaxa 4369 (2) on pages 202-204, DOI: 10.11646/zootaxa.4369.2.3, http://zenodo.org/record/1135678, {"references":["San Martin, G. & Parapar, J. (1990) Exogone acerata n. sp. (Exogoninae: Syllidae: Polychaeta), a new species without antennae from the Mediterranean Sea. Proceedings of the Biological Society of Washington, 103, 687 - 690.","Hartman, O. & Fauchald, K. (1971) Deep-water benthic polychaetous annelids off New England to Bermuda and other North Atlantic Areas. Part II. Allan Hancock Monographs in Marine Biology, 6, 1 - 327.","Claparede, E. (1868) Les annelides chetopodes du Golfe de Naples. Memories de la Societe de Physique et d'Histoire Naturelle de Geneve, 19, 313 - 584.","Webster, H. E. (1879) The Annelida Chaetopoda of the Virginian coast. Transactions of the Albany Institute, 9, 202 - 269.","San Martin, G. (2003) Anelidos Poliquetos. Familia Syllidae Grube, 1850. Museo Nacional de Ciencias Naturales, CSIC, Madrid, 554 pp.","San Martin, G., Ceberio, A. & Aguirrezabalaga, F. (1996) Exogone species (Polychaeta: Syllidae: Exogoninae) from the Capbreton Canyon (Bay of Biscay, NE Atlantic). Cahiers de Biologie Marine, 37, 249 - 258."]}

Prosphaerosyllis danovaroi Langeneck, Musco & Castelli n. sp. (Figure 6) Material examined. Holotype (MSNP: P/253/V): St. 11, Sardinian Slope, 600 m depth. Paratypes: St. 8: 2 individuals (MSNP: P/239/V); St. 11: 3 individuals (MSNP: P/237/V; P/3887; P/3888); St. 13: 1 individual (MSNP: P/3889). Description. All individuals lack pygidium. Holotype 2 mm long for 28 chaetigers, 0.16 mm maximum width. Body elongated, thread-like; anterior segments short, more elongated after proventricle, giving a moniliform appearance (Fig. 6a). Dorsal papillae small, scattered, not very conspicuous. Prostomium small, oval, fused with palps, with a small, pointed median antenna; lateral antennae smaller than median antenna, with rounded tip. Four small eyes in open trapezoidal arrangement, only seen in two paratypes (Fig. 6g). Palps entirely fused, covered by several, distinct papillae. Peristomial and dorsal cirri very small, papilliform, becoming slightly more elongated posteriorly. Parapodia well-developed, conical, each with single dorsal simple chaeta, ventral simple chaeta and up to seven compound chaetae on anterior parapodia, diminishing progressively to five posteriorly. Compound chaetae hemigomph, with both hinges of shafts almost of same length (Fig. 6c); blades approximately 5 µm long, short, slightly hooked, unidentate, smooth. Dorsal simple chaetae slightly hooked, slightly spinulated subdistally (Fig. 6d); ventral simple chaetae similar in shape, distinctly thinner, smooth (Fig. 6e). Aciculae robust, thick, with widened subdistal region and slightly deviated tip (Fig. 6f). Pharynx relatively short and wide, through three chaetigers. Small, triangular, thin tooth, located close to pharyngeal opening (Fig. 6g), not seen in holotype and other paratypes. Proventricle long and wide, barrel-shaped, through four chaetigers (Fig. 6a), with 20–23 cell rows. Etymology. The new species is dedicated to Prof. Roberto Danovaro, in recognition of his important scientific contributions to the knowledge of the Mediterranean deep-sea. Distribution. Western Mediterranean Sea: Sea of Sardinia (type locality), Tyrrhenian Sea. Remarks: One of the paratypes is a mature female, with very large intra-coelomic oocytes from chaetiger 10 to chaetiger 27. Individuals from the shallowest station (St. 8) show four very small, black eyes in trapezoidal arrangement. Prosphaerosyllis danovaroi n. sp. resembles Prosphaerosyllis giandoi (Somaschini & San Martín 1994) in the extremely small size of antennae and cirri, as well as the hemigomph articulation of compound chaetae and the moniliform body. However, it differs in the absence of eyes (which may be present but being very small) and eyespots (four very large eyes and two eyespots in P. giandoi), in the blades of compound chaetae (5 µm in P. danovaroi n. sp. for 9–10 µm in P. giandoi), in the body size (0.16 mm width, 28 chaetigers an incomplete individual of P. danovaroi n. sp. for 0.12 mm width, 23 chaetigers a complete individual of P. giandoi) and in the bathymetric distribution, circalittoral to bathyal (110–1200 m depth) in P. danovaroi n. sp. vs. shallow waters (0– 30 m depth) for P. giandoi (Somaschini & San Martín 1994; Olivier et al. 2012). Prosphaerosyllis adelae San Martín, 1984b is also characterised by falcigers with hemigomph articulation and by papilliform cirri, but in this species the prostomium is usually retracted under the peristomium, and aciculae show a subdistal crown of spines. Also Prosphaerosyllis opisthoculata (Hartmann-Schröder, 1979) is characterised by hemigomph falcigers, but dorsal cirri are distinctly larger, and this species is provided with well-developed eyes hidden by the dorsal part of the peristomium. All remaining species of the genus Prosphaerosyllis are characterised by heterogomph articulation of falcigers and larger dorsal cirri and therefore can be readily distinguished from P. danovaroi n. sp. (San Martín 2005; Ding and Westheide 2008; Fukuda et al. 2009; Çinar et al. 2011; Olivier et al. 2012; Salcedo et al. 2016).

Erinaceusyllis barbarae Langeneck, Musco & Castelli n. sp. (Figures 1–2) Material examined. Holotype (MSNP: P/236/V): St. 4, Southern Adriatic Sea, 1200 m depth; Paratypes: same data as holotype: 1 individual (MSNP: P/257/V); St. 8: 2 individuals (MSNP: P/243/V). St. 11: 2 individuals (MSNP: P/252/V; P/256/V). Description. Holotype atokous, entire, with relatively stout and robust body, 26 chaetigers for ca. 2 mm long, maximum width 0.18 mm (Fig. 1a, b); paratype entire, epitokous male, 30 chaetigers, ca. 2 mm long, 0.20 mm maximum width (Fig. 1c). Dorsum covered by small, scattered papillae. Prostomium oval, with four reddish eyes in trapezoidal arrangement and two anterior black eyespots (apparently absent in some paratypes). Antennae with bulbous base, last 2/3 briskly shrunken in a small tip; central antenna inserted slightly posteriorly to posterior eyes, as long as prostomium; lateral antennae ca. half long as median one, inserted on anterior margin (Fig. 1b). Palps shorter than prostomium, lacking noticeable papillae. Peristomium shorter than subsequent segments, covering dorsally prostomial posterior margin; single pair of peristomial cirri, similar in size and shape to lateral antennae. Dorsal cirri similar to antennae on anterior chaetigers, becoming more elongated towards pygidium, with gradually less shrunken tip (Fig. 1a), absent at chaetiger 2 (Fig. 1a, b, c). Parapodia rectangular to conical, well developed, with 7–8 compound and two simple chaetae; number of chaetae per parapodium diminishing posteriorly to five compound and two simple chaetae in posterior parapodia. Compound chaetae heterogomph, with shafts marginally smooth; blades all unidentate, distally slightly hooked (Fig. 2a, 2b). A single, most dorsal compound chaeta with distinctly elongated, slightly sinuous blade on each parapodium (Fig. 2a, b); 40 µm long on anterior parapodia, provided with several thin spines basally, 35 µm long, smooth, on posterior parapodia. Remaining falcigerous chaetae with smooth blade ranging from 25 to 18 µm on anterior parapodia, 23 to 15 µm on posterior parapodia (Fig. 2a, 2b). Dorsal simple chaetae occurring throughout the whole body, unidentate, robust, slightly sinuous and with very short distal spines (Fig. 2c); ventral simple chaetae only in posterior parapodia, thinner than dorsal one, smooth, unidentate (Fig. 2d). Acicula solitary, acuminate, with slightly enlarged sub-distal part (Fig. 2e). Pharynx short, approximately half as wide as the proventricle, across three chaetigers, tooth not visible (holotype) or relatively small, triangular, pointed, near to pharynx opening (paratype). Proventricle long, wide, barrel-shaped, and extending across four chaetigers, with about 19–20 muscle cell rows. Pygidium small, with two elongated cirri, approximately 2½ long as posterior dorsal cirri (Fig. 2f). Paratype with long capillary notochaetae and large intracoelomic sperm packages from chaetiger 8 to 23 (Fig. 1c). Etymology. This species is friendly dedicated to Dr. Barbara Mikac, in recognition of her important contribution to the knowledge on Mediterranean polychaetes, especially from the Adriatic Sea. Distribution. Mediterranean Sea: Adriatic Sea (type locality), Tyrrhenian Sea, Sea of Sardinia; from 110 to 1200 m depth. Remarks. Based on the chaetae with unidentate sabre-like blades, E. barbarae n. sp. resembles Erinaceusyllis serratosetosa (Hartmann-Schröder, 1982) and Erinaceusyllis ettiennei San Martín, 2005. It differs from the former in lacking spinulation in most compound chaetae and as antennae and dorsal cirri in the anterior part of the body are shorter and thicker. Erinaceusyllis ettiennei differs from the new species in having all blades with a more pronounced spinulation, which gradually decreases dorsoventrally. Moreover, E. ettiennei is smaller than the new species and has longer antennae and dorsal cirri in the anterior part of the body. Erinaceusyllis barbarae n. sp. can be easily distinguished from the remaining Mediterranean Erinaceusyllis based on their compound chaetae: Erinaceusyllis belizensis (Russell, 1989) and Erinaceusyllis cryptica (Ben-Eliahu, 1977) have bidentate blades (San Martín 2003), while Erinaceusyllis erinaceus (Claparède, 1863) has unidentate, distinctly shorter blades, with a less pronounced dorso-ventral gradation (Verdes et al. 2013). Moreover, contrary to the new species, the species of Erinaceusyllis typically occur in shallow water environments (San Martín 2005; Ramos et al. 2010; Lucas et al. 2017), even if some abyssal species originally assigned to the genus Sphaerosyllis Claparède, 1863, as Sphaerosyllis ridgensis Blake & Hilbig, 1990, and Sphaerosyllis ruthae San Martín, 2004 could actually belong to Erinaceusyllis (G. San Martín, pers. comm.). Sphaerosyllis ruthae, originally described from abyssal depths (> 4000 m) in Alaska shows some similarities with E. barbarae n. sp. as regards the shape of chaetae, that are very long, unidentate and with poorly developed ventral spinulation, but it clearly differs from the new species in the absence of eyes and in the proventricle shorter than the pharynx (longer than the pharynx in E. barbarae n. sp.).

Exogone naidina ��rsted, 1845 Exogone naidina ��rsted 1845: 20, Pl. 2; San Mart��n 1984a: 208, pl. 46. Exogone (Exogone) naidina San Mart��n 2003: 262 ���265, Figs 142���143. San Mart��n 2005: 130 ���131, Fig. 79. Syllis longiseta Gosse 1855: 32 ���33, Pl. 4, Figs 14���21. Gossia longiseta Quatrefages 1866: 49. Exogone gemmifera Pagenstecher 1862: 267; Fauvel 1923: 305, Figs 117a���d; Day 1967: 274, Figs 12.10 p.v.; Ben-Eliahu 1977: 78, Fig. 7. Exogone kefersteinii Clapar��de 1863: 42 ���44, pl. 12, Figs 3���6. Schmardia chauseyana Quatrefages 1866: 65 ���66, Pl. 8, Figs 16���17. Paedophylax levis Bobretzky 1870: 234 ���238, Figs 54���57. Material examined. St. 8: 3 individuals. Distribution. Allegedly cosmopolitan (San Mart��n 2003). Remarks. The examined material morphologically corresponds to E. naidina as described by San Mart��n (2003). The extremely wide geographical distribution, as well as the wide range of ecological conditions where this species occurs, however, led to speculate that it may actually represent a species complex, as supported by the occurrence of diploid and a tetraploid form in shallow Mediterranean waters (Cognetti Varriale, 1967). Further molecular studies, together with detailed morphological analyses are needed to clarify the taxonomic status of this widely distributed species., Published as part of Langeneck, Joachim, Musco, Luigi, Busoni, Giulio, Conese, Ilaria, Aliani, Stefano & Castelli, Alberto, 2018, Syllidae (Annelida: Phyllodocida) from the deep Mediterranean Sea, with the description of three new species, pp. 197-220 in Zootaxa 4369 (2) on page 202, DOI: 10.11646/zootaxa.4369.2.3, http://zenodo.org/record/1135678, {"references":["Orsted, A. E. (1845) Uber die Entwickelung der Jungen bei einer Annelide und uber die ausseren Unterschiede zwischen beiden Geschlechtern. Archiv fur Naturgeschichte Berlin, 11, 20 - 23.","San Martin, G. (1984 a) Estudio biogeografico, faunistico y sistematico de los poliquetos de la familia silidos (Syllidae: Polychaeta) en Baleares. PhD Thesis, Universidad Complutense de Madrid, Madrid, 529 pp.","San Martin, G. (2003) Anelidos Poliquetos. Familia Syllidae Grube, 1850. Museo Nacional de Ciencias Naturales, CSIC, Madrid, 554 pp.","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","Gosse, P. H. (1855) Notes on some new or little known marine animals. Annals and Magazine of Natural History, Series 2, 16, 27 - 35.","Quatrefages, A. de (1866) Histoire naturelle des Anneles marins et d'eau douce. Annelides et Gephyriens. Vol. 2. Librarie Encyclopedique de Roret, Paris, 794 pp.","Pagenstecher, H. A. (1862) Untersuchungen uber niedere Seethiere aus Cette. Zeitschrift fur wissenschaftliche Zoologie, 12, 265 - 311.","Fauvel, P. (1923) Polychetes errantes. Faune de France 5. Librairie de la Faculte des Sciences, Paris, 488 pp.","Day, J. H. (1967) A Monograph on the Polychaeta of Southern Africa, vol. 29. Trustees of the British Museum (Natural History), London, 878 pp.","Ben-Eliahu, M. N. (1977) Polychaete cryptofauna from rims of similar intertidal vermetid reefs on the Mediterranean coast of Israel and in the Gulf of Elat: Exogoninae and Autolytinae (Polychaeta Errantia: Syllidae). Israel Journal of Zoology, 26, 59 - 99.","Claparede, E. (1863) Beobachtungen uber Anatomie und Entwicklungsgeschichte wirbelloser Thiere an der Kuste von Normandie angestellt. W. Engelmann, Leipzig, 120 pp. https: // doi. org / 10.5962 / bhl. title. 10030","Bobretzky, N. (1870) Materials to the fauna of the Black Sea (Annelida Polychaeta). Memoires de la Societe des Naturalistes de Kiew, 1, 188 - 274. [in Russian]","Cognetti Varriale, A. M. (1967) Citotassonomia di alcune specie di Exogonine (Polychaeta, Syllidae). Atti della Societa dei Naturalisti e Matematici di Modena, 98, 106 - 108."]}

Syllis profunda Cognetti, 1955 stat. nov. (Figure 7) Syllis variegata profunda Cognetti 1955: 3, Fig. 2b; Cognetti 1957: 20 ���21, Fig. 4b. Syllis alternata Moore, 1908 sensu ��inar & Gambi 2005: 754 ���755. ? Syllis alternata Moore, 1908 sensu ��inar & Ergen 2003 partim: 777���778. Material examined. Holotype: SZN-POL31: Grotta Azzurra, 100 m (04/09/1955). Additional material: St. 7: 3 individuals; St. 8: 2 individuals; St. 9: 1 individual. Description. Holotype with regenerating anterior end, 11.3 mm long, 0.29 mm wide for 90 chaetigers. Prostomium (regenerated) oval, palps approximately 1.5x as long as prostomium; four reddish eyes in subtrapezoidal arrangement. Median antenna with 22 articles, lateral antennae with 15 articles. Dorsal cirri slender, moniliform, alternating in length, with 25���49 articles anteriorly, 20���40 articles at mid-body, and 28���30 articles posteriorly. Anterior parapodia with 6���8 compound chaetae, two distinctly longer, 2���4 of intermediate size and two short (Fig. 7a); mid-body parapodia with 5���6 compound chaetae, one long, 3���4 intermediate and one short (Fig. 7c); posterior parapodia with 5���6 compound chaetae, one longer, two intermediate, 2���3 short (Fig. 7e). Blades of compound chaetae 42 to 17 ��m long, strongly bidentate, with subdistal tooth similar in size to distal one, and a coarse, moderately long ventral serration. Simple chaetae absent. Parapodia well-developed: anterior parapodia with 3 aciculae of similar thickness, central one slightly thicker and longer (Fig. 7b); midbody parapodia with 2 aciculae, larger acicula with tip progressively broad, smaller acicula pointed, straight (Fig. 7d); posterior parapodia with single, thick acicula, distally pointed (Fig. 7f), protruding out from parapodial lobes. Pharynx and proventricle impossible to notice in the regenerating individual. Specimens from northern Tyrrhenian Sea (Fig. 7g) with very long, relatively wide pharynx, through nine chaetigers, with a small tooth close to opening; proventricle long, barrel-like, through 8 chaetigers, with ca. 35���40 muscle cell rows. Largest entire individual measuring ca. 20 mm long, 0,60 mm wide for 136 chaetigers, with up to 12 compound chaetae anteriorly, 10 at mid-body, and 8 posteriorly. Chaetae and aciculae as in holotype; anterior parapodia with three aciculae, simple chaetae always absent. Colour in living specimens pale brown to yellowish; yellowish when preserved. Distribution. Mediterranean Sea, from the Gulf of Naples (Cognetti 1955) to the Northern Tyrrhenian Sea (present data) and probably Levant Sea as S. alternata in ��inar & Ergen (2003); on hard and soft circalittoral bottoms (90���180 m, our data), including assemblages dominated by Leptometra phalangium and sponges. Other records of S. alternata in deep environments probably correspond to S. profunda. Remarks. Syllis alternata was described by Moore (1908) from muddy bottoms between 15 and 350 m depth in the north Pacific Ocean and includes at least five cryptic Pacific species (Carr et al., 2011). In the Mediterranean, this species has been reported mostly from shallow, hard bottoms, such as calcareous algae and coralligenous bottoms (San Mart��n 2003); such clear differences in ecological requirements in respect to the original description suggest that these hard bottom records might possibly belong to a different, undescribed species. However, other Mediterranean records of S. alternata refer to circalitoral habitats, i.e. hard bottoms (100 m) of the Gulf of Naples (Cognetti 1955���as S. variegata profunda) and muddy bottoms (90 m) of the Eastern Mediterranean Sea (��inar & Ergen 2003). It is worth noting that the type material of S. alternata from the Pacific Ocean, shows pseudo-spiniger compound chaetae (Licher, 1999), which are neither present in the shallow-water, nor in the deep-water Mediterranean specimens. The examination of the holotype of S. variegata profunda Cognetti, 1955 showed that chaetal features are identical to the presently reported deep-water material, even if the dark pigmentation in peristomium reported by Cognetti (1955) is not visible anymore. This species was considered synonymous with S. alternata by ��inar and Gambi (2005); on the basis of the mentioned difference, we here consider S. variegata profunda a clearly different species, and in addition raise it to species rank as Syllis profunda Cognetti, 1955. The shallow-water Mediterranean specimens of Syllis alternata sensu San Mart��n (2003) differ from the deep water ones in having up to seven aciculae in the anterior parapodia (three in S. profunda), the blades of compound chaetae up to 60 ��m (up to 45 ��m in S. profunda) and the presence of simple chaetae (absent in S. profunda) (San Mart��n 2003). We here consider them as separate taxa, even if molecular analyses may be useful to correctly assess this taxonomic issue., Published as part of Langeneck, Joachim, Musco, Luigi, Busoni, Giulio, Conese, Ilaria, Aliani, Stefano & Castelli, Alberto, 2018, Syllidae (Annelida: Phyllodocida) from the deep Mediterranean Sea, with the description of three new species, pp. 197-220 in Zootaxa 4369 (2) on pages 209-211, DOI: 10.11646/zootaxa.4369.2.3, http://zenodo.org/record/1135678, {"references":["Cognetti, G. (1955) Ricerche sui Sillidi del Golfo di Napoli. IV. Osservazioni su specie criptiche e su nuove sottospecie geografiche o ecologiche. Pubblicazioni della Stazione Zoologica di Napoli, 26, 1 - 11.","Cognetti, G. (1957) I Sillidi del Golfo di Napoli. Pubblicazioni della Stazione Zoologica di Napoli, 30, 1 - 100.","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.","Cinar, M. E. & Gambi, M. C. (2005) Cognetti's syllid collection (Polychaeta: Syllidae) deposited at the Museum of the Stazione Zoologica \" Anton Dohrn \" (Naples, Italy), with descriptions of two new species of Autolytus. Journal of Natural History, 39, 725 - 762. https: // doi. org / 10.1080 / 00222930400001327","Carr, C. M., Hardy, S. M., Brown, T. M., Macdonald, T. A. & Hebert, P. D. N. (2011) A tri-oceanic perspective: DNA barcoding reveals geographic structure and cryptic diversity in Canadian polychaetes. PLoS ONE, 6, e 22232. https: // doi. org / 10.1371 / journal. pone. 0022232","San Martin, G. (2003) Anelidos Poliquetos. Familia Syllidae Grube, 1850. Museo Nacional de Ciencias Naturales, CSIC, Madrid, 554 pp.","Licher, F. (1999) Revision der Gattung Typosyllis Langerhans, 1879 (Polychaeta: Syllidae). Morphologie, Taxonomie und Phylogenie. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 551, 1 - 336."]}

Syllis parapari San Mart��n & L��pez, 2000 Syllis parapari San Mart��n & L��pez 2000: 426 ���429, Figs 1���2; San Mart��n 2003: 409 ���413, Figs 224���225. Langerhansia cornuta (Rathke, 1843) sensu Campoy 1982: 378 ���386; Pls. 34���35. Material examined. St. 8: 9 individuals; St. 10: 1 individual. Remarks. The specimens agree well with the description by San Mart��n (2003). The Mediterranean species of Syllis with spiniger-like chaetae show different ecological requirements and bathymetric distributions. Syllis parapari mainly occurs on circalittoral muddy sands and mud between 20 and 60 m (��inar & Ergen 2003; Faulwetter et al. 2011; Mikac 2015), being replaced by Syllis sp. 1 (present paper) in bathyal bottoms. The present ones represent the first records for the Tyrrhenian Sea and expand the species��� depth range towards deeper circalittoral environments. Distribution. Atlantic coast of the Iberian peninsula (San Mart��n 2003), Adriatic Sea (Mikac 2015), Eastern Mediterranean Sea (��inar & Ergen 2003; Faulwetter et al. 2011), and possibly Indopacific area (San Mart��n 2003; Aguado et al. 2008). In addition, a number of questionable Mediterranean records of S. cornuta probably refer to S. parapari, since the former does not occur in this sea (Licher 1999). However, these questionable records refer to a variety of Mediterranean bottoms, and may possibly belong to several different species (Mikac & Musco 2010; Mikac 2015). Therefore, the actual distribution of S. parapari, especially in the Mediterranean Sea, is currently unknown., Published as part of Langeneck, Joachim, Musco, Luigi, Busoni, Giulio, Conese, Ilaria, Aliani, Stefano & Castelli, Alberto, 2018, Syllidae (Annelida: Phyllodocida) from the deep Mediterranean Sea, with the description of three new species, pp. 197-220 in Zootaxa 4369 (2) on page 209, DOI: 10.11646/zootaxa.4369.2.3, http://zenodo.org/record/1135678, {"references":["San Martin, G. & Lopez, E. (2000) Three new species of Syllis (Syllidae: Polychaeta) from Iberian coasts. Cahiers de Biologie Marine, 41, 425 - 434.","San Martin, G. (2003) Anelidos Poliquetos. Familia Syllidae Grube, 1850. Museo Nacional de Ciencias Naturales, CSIC, Madrid, 554 pp.","Campoy, A. (1982) Fauna de Espana. Fauna de Anelidos poliquetos de la Peninsula Iberica. Publicaciones de la Universidad de Navarra, Serie Zoologica, 7, 1 - 400.","Faulwetter, S., Chatzigeorgiou, G., Galil, B. S. & Arvanitidis, C. (2011) An account of the taxonomy and distribution of Syllidae (Annelida, Polychaetes) in the eastern Mediterranean, with notes on the genus Prosphaerosyllis San Martin, 1984 in the Mediterranean. ZooKeys, 150, 281 - 326. https: // doi. org / 10.3897 / zookeys. 150.2146","Mikac, B. (2015) A sea of worms: polychaete checklist of the Adriatic Sea. Zootaxa, 3943 (1), 1 - 172. https: // doi. org / 10.11646 / zootaxa. 3943.1.1","Licher, F. (1999) Revision der Gattung Typosyllis Langerhans, 1879 (Polychaeta: Syllidae). Morphologie, Taxonomie und Phylogenie. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 551, 1 - 336.","Mikac, B. & Musco, L. (2010) Faunal and biogeographic analysis of Syllidae (Polychaeta) from Rovinj (Croatia, northern Adriatic Sea). Scientia Marina, 74, 353 - 370. https: // doi. org / 10.3989 / scimar. 2010.74 n 2353"]}

Parexogone wolfi (San Mart��n, 1991) (Figure 5) Exogone (Parexogone) wolfi San Mart��n 1991: 726, Fig. 6; San Mart��n et al. 1996: 252, Fig. 3; San Mart��n 2003: 243 ���244, Figs 129���130. Parexogone wolfi B��ggemann & Purschke 2005: 223 ���225, Fig. 2; B��ggemann 2009: 408 ���410, Figs 145���146; Barroso et al. 2017: 406 ���407, Fig. 3. ? Paedophylax longicirris Webster & Benedict 1887: 722, Figs 46���50. ? Exogone longicirris Perkins 1981: 1092, Fig. 11. ? Parexogone longicirris Lucas et al. 2017: 10 ���11, Fig. 2. ? Exogone furcifera Eliason 1962: 243 ���246, Fig. 11. ? Exogone (Parexogone) canyonincolae Sard�� et al. 2009: 15 ���17, Fig. 7. Material examined. St. 8: 4 individuals. St. 16: 3 individuals. St. 19: 2 individuals. Description. All individuals lacking pygidium; two with regenerating anterior end. Best preserved individual ca. 6 mm long for 40 chaetigers, 0.20 mm wide. Prostomium wider than long, often hidden under dorsal part of peristomial segment, four rounded, relatively large eyes in trapezoidal arrangement (absent in regenerating individuals). Palps ca. twice as long as prostomium, entirely fused, clearly pointed; antennae well-developed, median one slightly longer than palps, lateral antennae ca. half as long as median one. Dorsal cirri oval, small, present in all chaetigers. Parapodia well-developed, with 8���14 compound chaetae, blades bidentate. Two spinigerlike chaetae with distinctly long, slightly sinuous blade (45���55 ��m in the anterior part, 50���70 ��m in the midbody, 30���45 ��m in the posterior part of the body), with a strong serration in the distal part, less evident towards basal part (Fig. 5b). Several falcigers on each parapodium, with distinctly shorter blades and strong serration, with some longer spines distally, decreasing in size from the dorsal part of parapodium to the ventral one, approximately 15��� 25 ��m in the anterior part of the body, 10���20 ��m in the midbody, 15���8 ��m in the posterior part of the body (Fig. 5c). Pharynx slender, longer than proventriculum, through 4 segments, bearing a strong, triangular tooth on anterior margin; proventricle short, through two segments approximately, with 15���17 cell rows. Distribution. Western Atlantic Ocean (San Mart��n 1991; Barroso et al. 2017); Eastern Atlantic Ocean (San Mart��n et al. 1996; B��ggemann 2009); Pacific Ocean (dubious) (San Mart��n 2005); Eastern Mediterranean Sea (Simboura & Zenetos 2005); from ca. 100 m depth (Simboura & Zenetos 2005) to more than 5000 m depth (B��ggemann 2009). This is the first record of the species for the Western Mediterranean. Remarks. Parexogone wolfi is one of the most widespread deep-water Exogoninae and shows remarkably wide depth range adaptation (San Mart��n 2003). The available descriptions, however, highlight slight differences between individuals from different areas, which might represent a clue of cryptic speciation (Barroso et al. 2017). For instance, shallow water (8 m depth) Pacific individuals are distinctly thinner, with a couple of additional eyespots and shorter spiniger-like chaetae in respect to the original description (San Mart��n 2005), which in our opinion suggests that they may represent an undescribed species. Parexogone wolfi closely resembles P. canyonincolae, which differs mainly in measuring 2.5 mm long for 50 chaetigers, (ca. 6 mm and 40 chaetigers in P. wolfi). Therefore, the possibility that P. canyonincolae might just represent a juvenile stage of P. wolfi cannot be ruled out. On the other hand, Exogone longicirris Webster & Benedict, 1887 has been recently assigned to Parexogone, and closely resembles P. wolfi. The main differences are only a slightly lower number of proventricular cell rows (11���14 vs 15���21) and a less pronounced spinulation along the blade edge (Eliason 1962; Lucas et al. 2017). The spinulation of compound chaetae, however, shows geographical variability, as the Brazilian specimens examined by Barroso et al. (2017) show less pronounced spines than those reported in the original description (San Mart��n 1991), thus appearing closer to P. longicirris. Taking into account the current knowledge (including the similar depth range and geographical distribution), a synonymy between P. wolfi and P. longicirris cannot be ruled out., Published as part of Langeneck, Joachim, Musco, Luigi, Busoni, Giulio, Conese, Ilaria, Aliani, Stefano & Castelli, Alberto, 2018, Syllidae (Annelida: Phyllodocida) from the deep Mediterranean Sea, with the description of three new species, pp. 197-220 in Zootaxa 4369 (2) on pages 205-207, DOI: 10.11646/zootaxa.4369.2.3, http://zenodo.org/record/1135678, {"references":["San Martin, G., Ceberio, A. & Aguirrezabalaga, F. (1996) Exogone species (Polychaeta: Syllidae: Exogoninae) from the Capbreton Canyon (Bay of Biscay, NE Atlantic). Cahiers de Biologie Marine, 37, 249 - 258.","San Martin, G. (2003) Anelidos Poliquetos. Familia Syllidae Grube, 1850. Museo Nacional de Ciencias Naturales, CSIC, Madrid, 554 pp.","Boggemann, M. & Purschke, G. (2005) Abyssal benthic Syllidae (Annelida: Polychaeta) from the Angola Basin. Organisms Diversity and Evolution, 5 (Supplement 1), 221 - 226. https: // doi. org / 10.1016 / j. ode. 2004.11.006","Boggemann, M. (2009) Polychaetes (Annelida) of the abyssal SE Atlantic. Organism Diversity and Evolution, 9, 251 - 428. https: // doi. org / 10.1016 / j. ode. 2009.10.001","Barroso, R., De Paiva, P. C., De Matos Nogueira, J. M. & Veronesi Fukuda, M. (2017) Deep sea Syllidae (Annelida, Phyllodocida) from Southwestern Atlantic. Zootaxa, 4221 (4), 401 - 430. https: // doi. org / 10.11646 / zootaxa. 4221.4.1","Perkins, T. H. (1981) Syllidae (Polychaeta) principally from Florida, with descriptions of a new genus and twenty-one new species. Proceedings of the Biological Society of Washington, 93, 1080 - 1172.","Lucas, Y., Sikorski, A. & San Martin, G. (2017) Syllidae (Annelida) from the Boreal and sub-Arctic seas off Norway (North Sea, Norwegian Sea, Barents Sea). Journal of the Marine Biological Association of the U. K.. [published online] https: // doi. org / 10.1017 / S 002531541600182 X","Eliason, A. (1962) Die Polychaeten der Skagerrak-Expedition 1933. Zoologiska bidrag fran Uppsala, 33, 207 - 293.","Sarda, R., Gil, J., Taboada, S. & Gili, J. M. (2009) Polychaete species captured in sediment traps moored in northwestern Mediterranean submarine canyons. Zoological Journal of the Linnean Society, 155, 1 - 21. https: // doi. org / 10.1111 / j. 1096 - 3642.2008.00442. x","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","Simboura, N. & Zenetos, A. (2005) Increasing Polychaete diversity as a consequence of increasing research effort in Greek waters: new records and exotic species. Mediterranean Marine Science, 6, 75 - 88. https: // doi. org / 10.12681 / mms. 194"]}

Parexogone campoyi San Mart��n, Ceberio & Aguirrezabalaga, 1996 Exogone (Parexogone) campoyi San Mart��n et al. 1996: 252 ���255, Figs 4���5; San Mart��n 2003: 244 ���247, Figs 131���132. Parexogone campoyi Barroso et al. 2017: 408 ���411, Figs 4���6. Material examined. St. 5: 1 individual; St. 11: 4 individuals; St. 12: 8 individuals; St. 13: 9 individuals; St. 14: 3 individuals; St. 15: 1 individual; St. 17: 2 individuals; St. 18: 2 individuals; St. 20: 1 individual. Distribution. Eastern Atlantic Ocean (San Mart��n et al. 1996); Mediterranean Sea (Simboura & Zenetos 2005; Langeneck et al. 2017; present data); western Atlantic Ocean (Barroso et al. 2017). Remarks. The examined individuals correspond to the original description (San Mart��n et al. 1996). P. campoyi is the most abundant Syllidae in Mediterranean deep environments below 900 m depth analysed in this study., Published as part of Langeneck, Joachim, Musco, Luigi, Busoni, Giulio, Conese, Ilaria, Aliani, Stefano & Castelli, Alberto, 2018, Syllidae (Annelida: Phyllodocida) from the deep Mediterranean Sea, with the description of three new species, pp. 197-220 in Zootaxa 4369 (2) on page 205, DOI: 10.11646/zootaxa.4369.2.3, http://zenodo.org/record/1135678, {"references":["San Martin, G., Ceberio, A. & Aguirrezabalaga, F. (1996) Exogone species (Polychaeta: Syllidae: Exogoninae) from the Capbreton Canyon (Bay of Biscay, NE Atlantic). Cahiers de Biologie Marine, 37, 249 - 258.","San Martin, G. (2003) Anelidos Poliquetos. Familia Syllidae Grube, 1850. Museo Nacional de Ciencias Naturales, CSIC, Madrid, 554 pp.","Barroso, R., De Paiva, P. C., De Matos Nogueira, J. M. & Veronesi Fukuda, M. (2017) Deep sea Syllidae (Annelida, Phyllodocida) from Southwestern Atlantic. Zootaxa, 4221 (4), 401 - 430. https: // doi. org / 10.11646 / zootaxa. 4221.4.1","Simboura, N. & Zenetos, A. (2005) Increasing Polychaete diversity as a consequence of increasing research effort in Greek waters: new records and exotic species. Mediterranean Marine Science, 6, 75 - 88. https: // doi. org / 10.12681 / mms. 194","Langeneck, J., Busoni, G., Aliani, S. & Castelli, A. (2017) Deep-sea polychaetes (Annelida) from the Malta Escarpment (western Ionian Sea). The European Zoological Journal, 84, 142 - 152. https: // doi. org / 10.1080 / 24750263.2017.1287964"]}

The honeycomb worm Sabellaria alveolata is a gregarious tube-dwelling polychaete that builds remarkable biogenic reefs in marine coastal waters. Sabellaria alveolata reefs are considered valuable marine habitats requiring protection measures for their conservation, as they play a key role in the functioning of coastal ecosystems. Sabellarid reefs are extensively developed along the Atlantic coasts of Europe and reported for the Mediterranean Sea and the Italian coasts, where large reefs have been recorded in several localities. Fragmentary information is available on their health status, Sabellaria reefs thus being listed as “Data Deficient” in the Red List of Marine Habitats. To fill this knowledge gap, this study focused on the analysis of the structure of three reefs found along the southern coast of Sicily. In particular, we aimed to assess their phases with respect to the natural cycle that characterizes the sabellarid reefs. Reef features were analyzed both on the macroscale, based on the bioconstruction size (diameter and thickness) and degree of fragmentation, and on the microscale, based on the measurement of worm density, opercular length and sand porch presence. This study reveals relevant differences among reefs of the studied locations. These differences we attributeto the temporal shift linked to the natural reef phases, albeit further analyses are needed to understand the possible effect of natural and anthropogenic sources of variation on the Southern Sicilian reefs. In conclusion, Sabellaria reefs are a unique and persistent habitat along the Sicilian coast requiring proper management and conservation measures.

Este artículo contiene 10 páginas, 5 figuras, 1 tabla., The process of site selection and spatial planning has received scarce attention in the scientific literature dealing with marine restoration, suggesting the need to better address how spatial planning tools could guide restoration interventions. In this study, for the first time, the consequences of adopting different restoration targets and criteria on spatial restoration prioritization have been assessed at a regional scale, including the consideration of climate changes. We applied the decision-support tool Marxan, widely used in systematic conservation planning on Mediterranean macroalgal forests. The loss of this habitat has been largely documented, with limited evidences of natural recovery. Spatial priorities were identified under six planning scenarios, considering three main restoration targets to reflect the objectives of the EU Biodiversity Strategy for 2030. Results show that the number of suitable sites for restoration is very limited at basin scale, and targets are only achieved when the recovery of 10% of regressing and extinct macroalgal forests is planned. Increasing targets translates into including unsuitable areas for restoration in Marxan solutions, amplifying the risk of ineffective interventions. Our analysis supports macroalgal forests restoration and provides guiding principles and criteria to strengthen the effectiveness of restoration actions across habitats. The constraints in finding suitable areas for restoration are discussed, and recommendations to guide planning to support future restoration interventions are also included., This study was funded by the EASME–EMFF (Sustainable Blue Economy) Project AFRIMED (http://afrimed-project.eu/, grant agreement N. 789059), supported by the European Community.

Este artículo contiene 11 páginas, 2 figuras, 2 tablas., Local, regional and global targets have been set to halt marine biodiversity loss. Europe has set its own policy targets to achieve Good Environmental Status (GES) of marine ecosystems by implementing the Marine Strategy Framework Directive (MSFD) across member states. We combined an extensive dataset across five Mediterranean ecoregions including 26 Marine Protected Areas (MPAs), their reference unprotected areas, and a no-trawl case study. Our aim was to assess if MPAs reach GES, if their effects are local or can be detected at ecoregion level or up to a Mediterranean scale, and which are the ecosystem components driving GES achievement. This was undertaken by using the analytical tool NEAT (Nested Environmental status Assessment Tool), which allows an integrated assessment of the status of marine systems. We adopted an ecosystem approach by integrating data from several ecosystem components: the seagrass Posidonia oceanica, macroalgae, sea urchins and fish. Thresholds to define the GES were set by dedicated workshops and literature review. In the Western Mediterranean, most MPAs are in good/high status, with P. oceanica and fish driving this result within MPAs. However, GES is achieved only at a local level, and the Mediterranean Sea, as a whole, results in a moderate environmental status. Macroalgal forests are overall in bad condition, confirming their status at risk. The results are significantly affected by the assumption that discrete observations over small spatial scales are representative of the total extension investigated. This calls for large-scale, dedicated assessments to realistically detect environmental status changes under different conditions. Understanding MPAs effectiveness in reaching GES is crucial to assess their role as sentinel observatories of marine systems. MPAs and trawling bans can locally contribute to the attainment of GES and to the fulfillment of the MSFD objectives. Building confidence in setting thresholds between GES and non-GES, investing in long-term monitoring, increasing the spatial extent of sampling areas, rethinking and broadening the scope of complementary tools of protection (e.g., Natura 2000 Sites), are indicated as solutions to ameliorate the status of the basin., This article was undertaken within the COST Action 15121 MarCons (http://www.marcons-cost.eu, European Cooperation in Science and Technology), the Interreg MED AMAre Plus (Ref: 8022) and the project PO FEAMP 2014-2020 Innovazione, sviluppo e sostenibilita ` nel settore della pesca e dell’acquacoltura per la Regione Campania (ISSPA 2.51). M.C.U., A.B. have been funded by the project MEDREGION (European Commission DG ENV/MSFD, 2018 call, Grant Agreement 110661/ 2018/794286/SUB/ENV.C2). Aegean Sea data were retrieved from the project PROTOMEDEA (www.protomedea.eu), funded by DG for Marine Affairs and Fisheries of the EC, under Grant Agreement SI2.721917. JB acknowledges support from the Spanish Ministry of Science and Innovation (Juan de la Cierva fellowship FJC 2018-035566-I)., With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S).

Invasive seaweeds are listed among the most relevant threats to marine ecosystems worldwide. Biodiversity hotspots, such as the Mediterranean Sea, are facing multiple invasions and are expected to be severely affected by the introduction of new non-native seaweeds in the near future. In this study, we evaluated the consequences of the shift from the native Ericaria brachycarpa to the invasive Asparagopsis taxiformis habitat on the shallow rocky shores of Favignana Island (Egadi Islands, MPA, Sicily, Italy). We compared algal biomass and species composition and structure of the associated epifaunal assemblages in homogenous and mixed stands of E. brachycarpa and A. taxiformis. The results showed that the biomass of primary producers is reduced by 90% in the A. taxiformis invaded habitat compared to the E. brachycarpa native habitat. The structure of the epifaunal assemblages displayed significant variations among homogenous and mixed stands. The abundance, species richness and Shannon-Wiener diversity index of the epifaunal assemblages decreased by 89%, 78% and 40%, respectively, from homogenous stands of the native E. brachycarpa to the invasive A. taxiformis. Seaweed biomass was the structural attribute better explaining the variation in epifaunal abundance, species richness and diversity. Overall, our results suggest that the shift from E. brachycarpa to A. taxiformis habitat would drastically erode the biomass of primary producers and the associated biodiversity. We hypothesize that a complete shift from native to invasive seaweeds could ultimately lead to bottom-up effects on rocky shore habitats, with negative consequences for the ecosystem structure, functioning, and the services provided.

Sabellida are widespread, diverse and abundant in marine benthic habitats. Their distribution patterns on hard-bottom substrates are poorly studied so far. Little is known about the factors influencing their distribution, including the protection regimes that are known to affect assemblage diversity. We analyzed hard-bottom Sabellida at 1.5 and 5 m depths at the Torre Guaceto Marine Protected Area (MPA) (SE Italy) to describe diversity and distribution patterns, and to identify potential factors influencing their distribution. The Sabellida diversity varied significantly among stations and was higher at 5 m depth. No relation with the protection regime was found. Among environmental variables, only sedimentation appeared related, suggesting that local trophic features might have influenced the observed pattern. Among habitat formers, only the macroalga Halimeda tuna significantly explained part of the observed variation, probably due to its role as a basibiont for some Sabellida taxa. Other predictor variables of Sabellida distribution were the abundances of some invertebrate taxa, especially Syllidae and some filter feeders such as Sabellariida and Cirripedia, probably due to shared ecological requirements, rather than a direct effect on Sabellida distribution. The relation with the Syllidae remains obscure so far, albeit some kind of interaction (including predator/prey interactions) between these two taxa cannot be excluded. Sabellida should be taken into account when analyzing patterns of biodiversity of hard-bottom environments.

Non-indigenous species (NIS) represent one of the most relevant threats to biodiversity, ecosystem functioning and human activities, and their occurrence and spread have been the subject of numerous works and revisions. However, the information available is rather confused for several taxa, including polychaetes, which are characterised by having a high number of cryptogenic and questionable species. This work aims at providing a revised checklist of alien polychaetes occurring along the coasts of Italy, based on the examination of newly collected and deposited material and on the critical analysis of published and gray literature, and whenever possible on the re-examination of historical material. Of the 86 polychaete species reported as NIS in Italian waters, 25 are confirmed as alien species, while 3 are cryptogenic, and 40 should be considered questionable. Finally, 18 species were excluded from non-indigenous species checklists, either because they are native, or because they represent misidentifications of other species. The high number of cryptogenic and questionable species points at the need of molecular studies and taxonomic revisions for the majority of polychaete taxa reported as NIS, in order to clarify their taxonomy, origin, introduction pathways and spreading patterns.

Marine bioconstructions are biodiversity-rich, three-dimensional biogenic structures, regulating key ecological functions of benthic ecosystems worldwide. Tropical coral reefs are outstanding for their beauty, diversity and complexity, but analogous types of bioconstructions are also present in temperate seas. The main bioconstructions in the Mediterranean Sea are represented by coralligenous formations, vermetid reefs, deep-sea cold-water corals, Lithophyllum byssoides trottoirs, coral banks formed by the shallow-water corals Cladocora caespitosa or Astroides calycularis, and sabellariid or serpulid worm reefs. Bioconstructions change the morphological and chemicophysical features of primary substrates and create new habitats for a large variety of organisms, playing pivotal roles in ecosystem functioning. In spite of their importance, Mediterranean bioconstructions have not received the same attention that tropical coral reefs have, and the knowledge of their biology, ecology and distribution is still fragmentary. All existing data about the spatial distribution of Italian bioconstructions have been collected, together with information about their growth patterns, dynamics and connectivity. The degradation of these habitats as a consequence of anthropogenic pressures (pollution, organic enrichment, fishery, coastal development, direct physical disturbance), climate change and the spread of invasive species was also investigated. The study of bioconstructions requires a holistic approach leading to a better understanding of their ecology and the application of more insightful management and conservation measures at basin scale, within ecologically coherent units based on connectivity: the cells of ecosystem functioning.

Ecological indicators likely constitute the mainstream tools in assessing the quality of aquatic ecosystems as they condense composite biological information into single measures, easier to handle for environmental managers and more understandable for non-scientific users. However, sampling settings can influence the performance of most indices, and their use is often constrained to specific habitat types. Average taxonomic distinctness (Delta(+)) and variation in taxonomic distinctness (Lambda(+)) may represent promising tools in overcoming sampling bias, and potentially applicable to a wide range of environmental contexts. In marine systems, such metrics showed higher sensitivity than classical indices in discriminating among perturbed and unperturbed conditions, though a number of studies found Delta(+) and Lambda(+) also varying along natural gradients, suggesting a lower ability to discern human-driven variations from natural variability than what expected. Here, analyzing existing data sets from previous impact assessment studies, we test the response of Delta(+) and Lambda(+) in detecting the effects of different sources of anthropogenic disturbance on marine mollusks and polychaetes from Mediterranean soft sediments and hard substrates. Our results showed that neither classical univariate analyses on Delta(+) and Lambda(+) values nor their associated statistical framework were able to discern among perturbed and unperturbed sites, highlighting a low sensitiveness of such metrics in detecting assemblage variations related to anthropogenic disturbance. Delta(+) and Lambda(+) are based on presence/absence data, and assume impacts being likely to induce variations in taxonomic structures of assemblages. As a consequence, they could experience reduced discrimination power when impacts mostly affect relative abundances of organisms rather than assemblage composition, or drive species replacement within higher taxa. Our results also showed that habitat type could strongly affect taxonomic relatedness of species within assemblages, and that this effect can vary among different organisms, suggesting that the departures from expectation of Delta(+) and Lambda(+) values might not be always univocally attributable to human perturbations, since possibly depending on habitat effects. Taxonomic distinctness indices can provide useful additional information on taxonomic diversity of assemblages, crucial to better address the wide concept of biological diversity. However, the effectiveness of such measures in disclosing the effects of human disturbance is still unclear, requiring further investigations especially on their potential application in defining the ecological status of coastal rocky systems. (C) 2010 Elsevier Ltd. All rights reserved.

Taxonomic Sufficiency (TS) has been proposed as a short-cut method to quantify changes of biological assemblages in environmental monitoring. However, issues about the efficacy of taxonomic surrogates in depicting long-term temporal patterns of marine assemblages are still scant. Here we report on the adoption of TS combined with data transformations to describe patterns of North Adriatic polychaete assemblages through 20 years. Univariate and multivariate analyses revealed large spatial temporal variation charactering the assemblages. The efficiency to discriminate between the two research periods (1990-1994 vs. 2004-2008) was reduced when data were analyzed at family and order level leading to misinterpreting the sources of assemblage variation. Further information was lost with data transforms. Families may represent appropriate assemblages' descriptors in long-term monitoring, but using TS coupled with data transformations could lead to hazardous loss of information. We suggest that periodical analysis at fine taxonomic level should be routinely alternated to long-term monitoring based on TS in order to check its effectiveness. (C) 2010 Elsevier Ltd. All rights reserved.

In the Northern Adriatic Sea, the combination of natural and anthropogenic processes causes periodic hypoxia and anoxia, which can cause mass mortality of benthic organisms. Here, we report the results of a 20-year monitoring programme carried out after an anoxic event in 1989 that caused benthic mass mortality over an area of about 1200 km(2). The recovery dynamics of the polychaete fauna was followed at three stations (including one sampled a year before the anoxic event). Samples (0.1 m(2) Van Veen grab, 2-mm sieve) were collected from 1989 to 1994 and from 2003 to 2008. A total of 6519 specimens belonging to 186 species were identified. The analyses of univariate biodiversity indexes highlighted higher temporal variation of assemblage diversity in the period following the dystrophic crisis, followed by higher stability in the next decade. PERMANOVA suggested that the highest component of assemblage variation belonged to the factor year. However, differences across years varied in magnitude, depending on stations and were portrayed by non-metric multidimensional scaling plots of each year's centroids for each of the three stations. SIMPER analysis identified the species most characterizing the assemblages in each year for each of the three stations. Our results highlight the importance of analysing long-term data sets in order to understand assemblage dynamics following strong disturbance events. Assuming the 1989 anoxia as the event determining the biodiversity change, and considering our outcomes, which suggest that the assemblages still show a pattern of non-random changes through years, our data indicate that the polychaete fauna is still recovering without having reached a pattern of among-years stability. Focusing on the biology of the species characterizing the different periods might help in understanding the ecological processes that have determined the observed pattern.

Taxonomic Sufficiency (TS) is a promising analysis technique, particularly in light of the current need for rapid and reliable procedures in marine impact assessment and monitoring. However, generalizations are still difficult and there are few studies comparing the effectiveness of TS under different environmental settings. The present study investigates whether reduced taxonomy can be used to detect natural and human-driven patterns of variation in mollusk and polychaete assemblages from subtidal soft and hard bottoms in the Mediterranean. Results showed that, unlike in polychaetes, mollusk families represent effective taxonomic surrogates across a range of environmental contexts. These findings suggest that the mechanisms behind TS in mollusks could act homogeneously across habitats and environmental conditions. In contrast, multiple factors could interact to determine the robustness of polychaetes to taxonomic aggregation. This study highlights the need to go beyond the current pragmatism in this field of work and focus on the reasons underlying TS effectiveness in order to provide a general framework on the application of taxonomic surrogates in marine systems.

Despite meiofauna being one of the most popular tool for detecting the ecological effects of different sources of impact, the application of structured experimental designs to this benthic component is typically neglected, especially in subtidal rocky shores. In this study, an asymmetrical design was used to detect hard-bottom meiofaunal abundance and biodiversity response to sewage discharge. Sampling was carried out at a depth of 3-4 m by SCUBA diving, by means of a modified manual corer. Six replicate cores were collected at three sites (80-100 m apart), at each of three locations (one purportedly impacted [I] and two controls [Cs]). A total of 84,994 specimens were collected. The outfall affected meiofaunal assemblages in terms of taxon richness, by determining a significant reduction of the number of taxa in the disturbed location, and community structure, by causing functional changes in terms of a decrease of the abundance of nematodes and an increase of the hydrozoan component. Nematodes and syllid polychaetes showed significant lower average abundance at I. Multivariate analyses showed that both meiofaunal assemblage and syllids were significantly different at I compared with Cs. The sewage outfall also affected patterns of spatial distribution at the scale of site (100 m apart) and of replicate units (centimetres apart), both in syllids and in nematodes. Our results provide evidence that the selection of multiple controls is crucial to prevent the widespread risk of Type II error, highlighting the need of more accurate experimental designs when dealing with meiofauna.

The hard bottom fauna of the marine protected area of Porto Cesareo (Salento Peninsula) was examined considering two representative benthic groups, Porifera and Polychaeta. Sampling was performed by SCUBA divers from the surface to a depth of 25 m in a variety of environments. Sponge and polychaete assemblages were rich and diversified, with a total of 160 taxa collected (66 and 94, respectively), representing the first large contribution to the knowledge of the two groups in the marine protected area. This was particularly true for polychaetes, 80% of which had not been previously reported in the literature for this area. The distribution of the species in the examined environments is also given.