A characteristic apomorphy of the Hesionidae are the cirrophores of the anteriorsegments, which are well-developed cup-like sheaths; the cirri of the subsequent segments insert into the parapodia directly, or with just a vestigial cirrophore.[2]
Systematics
As phyllodocids, the Hesionidae belong to the orderAciculata, 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). [3]
Numerous genera are still treated as Hesionidae incertae sedis, not reliably assignable to either of the three generally recognized hesionid subfamilies:[4]
^Salazar-Vallejo SI (2016) Elisesione, a new name for Wesenbergia Hartman, 1955, and the description of a new species (Annelida, Hesionidae). ZooKeys 632: 1-12. doi:10.3897/zookeys.632.9652.
Wikimedia Commons has media related to Hesionidae.
Pleijel, Fredrik; Rouse, Greg W.; Ruta, Christine; Wiklund, Helena & Nygren, Arne (2008): Vrijenhoekia balaenophila, a new hesionid polychaete from a whale fall off California. Zool. J. Linn. Soc.152(4): 625–634. doi:10.1111/j.1096-3642.2007.00360.x (HTML abstract)
