Hesionidae
Hesionidae are a family of phyllodocid "bristle worms" (class Polychaeta). They are (like almost all polychaetes) marine organisms. Most are found on the continental shelf; Hesiocaeca methanicola is found on methane ice, where it feeds on bacterial biofilms. A characteristic apomorphy of the Hesionidae are the cirrophores of the anterior segments, which are well-developed cup-like sheaths; the cirri of the subsequent segments insert into the parapodia directly, or with just a vestigial cirrophore. Systematics As phyllodocids, the Hesionidae belong to the order Aciculata, one of the three main clades of polychaetes. They appear to be part of the basal radiation of the main lineage of phyllodocids, alongside such families as the ragworms (Nereididae), the Pilargidae and Sphaerodoridae which are closely related to each other, the very ancient Syllidae, and perhaps the more advanced catworms (Nephtyidae). Numerous genera are still treated as Hesionidae incertae sedis, not reliably assignable to either of the three generally recognized hesionid subfamilies: Alikuhnia (including Anophthalmus Alikunhi, 1949 (non Schmidt, 1844: preoccupied)) Anoplonereis Giard, 1882 Cirrosyllis Schmarda, 1861 Elisesione Salazar-Vallejo, 2016 Friedericiella Hesiodeira Blake & Hilbig, 1990 Hesiolyra Blake, 1985 (sometimes separated in monotypic subfamily Hesiolyrinae) Hesionella Hartman, 1939 Heteropodarke Pleijel, 1999 Leocratides Ehlers, 1908 Mahesia Westheide, 2000 Neopodarke Hartman, 1965 Orseis Ehlers, 1864 Oxydromus Grube, 1855 Parahesione Pettibone, 1956 Parapodarke Czerniavsky, 1882 Periboea Ehlers, 1864 Podarke Ehlers, 1864 Pseudosyllidia Czerniavsky, 1882 Sinohesione Westheide, Purschke & Mangerich, 1994 Sirsoe Pleijel, 1998 Struwela Hartmann-Schröder, 1959 Footnotes References (2008): Vrijenhoekia balaenophila, a new hesionid polychaete from a whale fall off California. Zool. J. Linn. Soc. 152(4): 625–634. (HTML abstract) (1998): Recent views on the status, delineation, and classification of the Annelida. Am. Zool. 38(6): 953–964. PDF fulltext (2008): Hesionidae. Version of 2008-MAR-26. Retrieved 2009-FEB-23. Phyllodocida Taxa named by Adolph Eduard Grube Annelid families