Yolanda Lucas

Syllis Savigny in Lamarck, 1818, the type genus of Syllidae, is the largest and most diverse within the family. This genus presents many taxonomic, biogeographic, and phylogenetic problems due mainly to the lack of molecular data and morphological synapomorphies for many of the species, but also due to poor or inadequate descriptions. In order to improve our understanding of the genus, we have undertaken a morphological revision of Australian species, based on type material and material collected over years by the Australian Museum. This is the fourth paper dealing with this genus. Nine species are herein described, of which five are new records for Australia: Syllis ergeni Çinar, 2005; S. patersoni Soto, San Martín & Lucas, 2020; S. valida Grube, 1857; S. violacea Grube, 1870; and S. ypsiloides Aguado, San Martín & ten Hove, 2008. Three species already known from Australia are redescribed: S. heronislandensis (Hartmann-Schröder, 1991) n. comb.; S. parturiens Haswell, 1920; and S. cf. schmardiana Haswell, 1886. Syllis gantheaumensis (Hartmann-Schröder, 1979) n. comb. is raised to species level, since it was originally described as a subspecies of Typosyllis filidentata Hartmann-Schröder, 1962. We include an addendum with a list of species already treated in the previous papers on this genus, as well as some new synonymies after revision of types: Typosyllis (Typosyllis) gerhardi Hartmann-Schröder, 1980 and T. (T.) guildertonensis Hartmann-Schröder, 1979, as synonymous of Syllis busseltonensis (Hartmann-Schröder, 1982); T. (T.) raygeorgei Hartmann-Schröder, 1979 as synonymous of S. hyalina Grube, 1863; T. (T.) rockinghamensis Hartmann-Schröder, 1983 and T. (T.) pseudopapillata Hartmann-Schröder, 1991 as synonymous of S. pharobroomensis (Hartmann-Schröder, 1979). We also include a discussion of the genus and a key to Australian species.

Syllis Savigny in Lamarck, 1818, the type genus of Syllidae, is the largest and most diverse within the family. This genus presents many taxonomic, biogeographic, and phylogenetic problems due mainly to the lack of molecular data and morphological synapomorphies for many of the species, but also due to poor or inadequate descriptions. In order to improve the knowledge of the genus, we have undertaken a morphological revision of Australian species, based on type material and material collected over years by the Australian Museum. This is the third paper dealing with this family. Eighteen species are herein described, of which five are new and twelve are redescriptions of already known species, with four new combinations: Syllis imajimai, n. sp.; S. narranuk, n. sp.; S. noolinga, n. sp.; S. similisunzima, n. sp.; S. thylacine, n. sp.; S. busseltonensis (Hartmann-Schröder, 1982) n. comb.; S. patriciae (Hartmann-Schröder, 1981) n. comb.; S. pharobroomensis (Hartmann-Schröder, 1979) n. comb., S. pharynxcircunfusata (Hartmann-Schröder, 1979) n. comb, S. armillaris (O. F. Müller, 1771); S. augeneri Haswell, 1920; S. benelihauae (Campoy & Alquézar, 1982); S. hyalina Grube, 1863; S. cf. nigrescens Grube, 1878; S. profunda Cognetti, 1955; S. truncata Haswell, 1920; and S. variegata Grube, 1860.

Three new species of the genus Syllis Savigny in Lamarck, 1818, from the Chilean Patagonia are described, figured and discussed. The specimens were collected in boulders, sediment bottoms, Hacrocystis pyrifera holdfasts, and inside tubes of Chaetopterus cf. variopedatus. Syllis patagonica n. sp., is characterized by its color pattern, short, fusiform dorsal cirri, plenty of hyaline inclusions, acuminate posterior acicula, and compound chaetae with slightly bidentate falcigers. Syllis terraeignium n. sp., has similar compound chaetae, but dorsal cirri are longer than those of the above mentioned species, a long proventricle, and the posterior acicula are straight, pointed. Finally, Syllis patersoni n. sp., has a slender, elongated body, with moderately long dorsal cirri, plenty of hyaline inclusions, acuminate posterior acicula, and compound chaetae composed by falcigers and short spiniger-like.

Based on a census of the polychaete fauna of the Socotra Archipelago in the Indian Ocean we report here new findings on the genus Syllis Savigny in Lamarck, 1818. These ten species are newly recorded from this area: Syllis alternata Moore, 1908; Syllis bouvieri Gravier, 1900; Syllis broomensis (Hartmann-Schroder, 1979); Syllis compacta Gravier, 1900; Syllis crassicirrata (Treadwell, 1925); Syllis gerlachi (Hartmann-Schroder, 1960); Syllis hyalina Grube, 1863; Syllis lutea (Hartmann-Schroder, 1960); Syllis schulzi (Hartmann-Schroder, 1960); Syllis ypsiloides Aguado, San Martin & Ten Hove, 2008. Additionally, Syllis qamhiyn sp. nov. is described as a new species, characterized by its conspicuously thick and short dorsal cirri filled with a gelatinous substance and reduced number of compound chaetae from medium to posterior parapodia, with enlarged shafts and short blades which become almost unidentate and do not fuse with shafts. Following an examination of the holotype of S. bouvieri, its status as a valid species and not as synonym of Syllis prolifera Krohn, 1852, as considered by some authors (see Licher 1999) is confirmed, and a redescription is included.

In this paper, we report 10 species of Syllidae, collected in the Socotra Archipelago (Indian Ocean). They belong to eight different genera in four subfamilies namely, Syllinae: Haplosyllis Langerhans, 1879, Megasyllis San Martín, Hutchings & Aguado, 2008, Opisthosyllis Langerhans, 1879, Trypanosyllis Claparède, 1864; Eusyllinae: Eusyllis Malmgren, 1867, Odontosyllis Claparède, 1863; Exogoninae: Salvatoria McIntosh, 1885; and Autolytinae: Myrianida Milne Edwards, 1845. Trypanosyllis mercedesae n. sp., is here formally described and distinguished from congeners. Trypanosyllis richardi Gravier, 1900 is re-described, adding important taxonomic information to the original description, based on specimens collected from Djibouti (Gulf of Aden). We provide new insight into the reproduction of Megasyllis heterosetosa (Hartmann-Schröder, 1991) with the description of a specimen with an attached female dicerous stolon, full of oocytes. Odontosyllis polycera (Schmarda, 1861) is described because it is newly recorded for the Indian Ocean. We also provide some remarks about Myrianida pachycera (Augener, 1913), collected with a chain of stolons.

In this paper a description of Acritagasyllis longichaetosus, an enigmatic genus and species of Syllidae (Polychaeta), is given. The new genus is characterized by a lack of palps, eyes, and median antenna, having a single pair of tentacular (peristomial) cirri, distinct ventral cirri fused all along their length to parapodial lobes, a slender, coiled pharynx without trepan but with a pharyngeal tooth, compound chaetae with long shafts, distally enlarged and spinose, and long, filiform blades, quite similar to those belonging to members of the family Phyllodocidae. These characters are very unusual and unique among syllids. Some characters, like the presence of nuchal lappets, bayonet-shaped simple chaetae, and perhaps also the fusion of ventral cirri to parapodial lobes, bear some resemblance to those of species of Autolytinae. However, this new polychaete does not fit into this subfamily as it possesses ventral cirri, the chaetae are very different, and it lacks a trepan in the pharynx, nor can it be placed into any other subfamily, being an “incertae sedis” among the genera of Syllidae.