New species and records of the genus Syllis Savigny in Lamarck, 1818 (Annelida: Syllidae) from Socotra Archipelago (Indian Ocean).

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-Schröder, 1979); Syllis compacta Gravier, 1900; Syllis crassicirrata (Treadwell, 1925); Syllis gerlachi (Hartmann-Schröder, 1960); Syllis hyalina Grube, 1863; Syllis lutea (Hartmann-Schröder, 1960); Syllis schulzi (Hartmann-Schröder, 1960); Syllis ypsiloides Aguado, San Martín 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.

A new species and nine new records of Syllidae (Annelida) from the Socotra Archipelago (Indian Ocean).

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.