Ampharete undecima, a new deep-sea ampharetid (Annelida, Polychaeta) from the Norwegian Sea

Abstract

Ampharete undecima, a new deep-sea polychaete belonging to the family Ampharetidae, is described from slope depths in the Norwegian Sea. The new species is of small size, up to 5 mm long and 0.5 mm wide, and thus it may have been overlooked in previous studies. It is shown to be a common and widespread species in the Nordic Seas in depths ranging from 600–1650 m. The new species is referred to the genus Ampharete based on characteristics of the prostomium, the presence of buccal tentacles with secondary pinnulae, four pairs of branchiae arising from fused segment II + III, 12 thoracic uncinigerous segments, and a single pair of nephridial papillae on segment IV. The new species differs from all known species of Ampharete in having 11 rather than 12–28 abdominal uncinigerous segments.