Spio Fabricius, 1785

Bick, Andreas & Bastrop, Ralf, 2011, On the identity of Spio filicornis (O. F. Müller, 1776) — with the designation of a neotype, and the description of two new species from the North East Atlantic Ocean based on morphological and genetic studies, Zootaxa 2815, pp. 1-27 : 6

Genus Spio Fabricius, 1785

Type species: Nereis filicornis Müller, 1776

Type locality: Iluilârssuk, near Frederikshaab (Paamiut), West Greenland

Synonym: Paraspio Czerniavsky, 1881 ; type species: Spio decoratus Bobretzky, 1870 , by monotypy. Euspio McIntosh, 1915 ; type species: Euspio mesnili McIntosh, 1915 .

Diagnosis. Prostomium anteriorly rounded or slightly incised; branchiae present from chaetiger 1, to near posterior end; hooded hooks on middle and posterior neuropodia; metameric dorsal ciliated organs present; pygidium with four anal cirri.

Description. Prostomium anteriorly rounded or slightly incised, lacking frontal or lateral horns; eyes present or absent; digitiform occipital antenna absent, but posterior portion of prostomium may be raised or inflated. Nuchal organs with ciliated bands of different shapes and lengths posterolateral and posterior to prostomium, extending to chaetiger 2 or 3. Metameric dorsal ciliated organs present. Branchiae present from chaetiger 1, continuing almost throughout body, completely separate from or basally fused with notopodial lamella, often reduced in size on chaetiger 1. Notochaetae and anterior neurochaetae all capillaries; capillaries, hooded hooks and inferior sabre chaetae on middle and posterior chaetigers. Pygidium with 4 anal cirri.