Unciolidae of Deep-Sea Iceland (Amphipoda, Crustacea)

Abstract

An overview of North Atlantic Unciola Say, 1818 is provided along with the description of two new species, U. conchicola sp. nov. and U. icelandica sp. nov. Both deep-sea species were collected living sympatrically at an almost 2000 m depth in the Iceland Basin, southwest of Iceland, each showing a vertical distribution of more than 1 km. In addition to the wide depth range, U. icelandica sp. nov. also shows a broad geographic distribution of more than 1000 km. Unciola conchicola sp. nov. was seen to attach its tubular domicile to the inner cavity of a gastropod shell; however, no specific lifestyle information is known for the species U. icelandica sp. nov. Both species present novel characters for the genus: in U. conchicola sp. nov., the epimeral plates 1–3 have acute projections angled ventrally, while in U. icelandica sp. nov., the male antenna 2 pedunclar article 2 is developed into a distinct phalange. The large amount of unciolid material allowed for ontogentic studies. The material of U. planipes Norman, 1867 was investigated. Changes from juvenile to adult specimens of Neohela monstrosa (Boeck, 1861) are discussed. A key is provided to the eight North East Atlantic species of Unciola.