A revision of Hesiospina (Psamathini,Hesionidae, Polychaeta)

Hesiospina Imajima and Hartman, 1964 Imajima, M and Hartman, O. 1964. The polychaetous annelids of Japan. Part 1. Allan Hancock Foundation Publications, Occasional Paper, 26: 1–166.  Google Scholar] (Psamathini, Hesionidae, Polychaeta) is revised based on examination of all available types, other museum specimens and a large number of newly collected specimens from world-wide areas. Two species are recognized and redescribed, Hesiospina aurantiaca (Sars, 1862 Sars, M. 1862. Uddrag af en af detaillerade Afbildningar ledsaget udførlig Beskrivelse over følgende Norske Annelider. Forhandlinger i Videnskabsselskabet i Kristiania, 1862: 87–95.  Google Scholar]), new combination, and H. vestimentifera Blake, 1985 Blake, J. A. 1985. Polychaeta from the vicinity of deep-sea geothermal vents in the eastern Pacific. I. Euphrosinidae, Phyllodocidae, Hesionidae, Nereididae, Glyceridae, Dorvilleidae, Orbiniidae, and Maldanidae. Bulletin of the Biological Society of Washington, 6: 67–101.  Google Scholar]. The currently used name Hesiospina similis (Hessle, 1925 Hessle, C. 1925. Einiges über die Hesioniden und die Stellung der Gattung Ancistrosyllis. Arkiv för Zoologi, 17: 1–36.  Google Scholar]) is treated as a junior synonym of both Hesiospina aurantiaca and Castalia longicornis Sars, 1862 Sars, M. 1862. Uddrag af en af detaillerade Afbildningar ledsaget udførlig Beskrivelse over følgende Norske Annelider. Forhandlinger i Videnskabsselskabet i Kristiania, 1862: 87–95.  Google Scholar]. A lectotype is designated for H. aurantiaca, and the same specimen is used as neotype for C. longicornis, making the two objective synonyms. Hesiospina aurantiaca is widely distributed and recorded from the Caribbean, Gulf of Mexico, European Atlantic and Mediterranean waters, Japan, Papua New Guinea, the Great Barrier Reef, and New Caledonia, mainly from shallow waters, but down to over 500?m depth. Whereas there are some differences between populations from different regions, including distribution of uni- and bidentate chaetae, the different populations are not characterized by any obvious apomorphies and are treated as a single species. Hesiospina vestimentifera is associated with hydrothermal vents and is widely distributed in the east Pacific.