Leptonerilla diplocirrata, a new genus and species of interstitial polychaetes from the island of Hainan, south China (Nerillidae)

Abstract

A new nerillid polychaete, Leptonerilla diplocirrata, new genus and species, is described from subtidal sandy sediments of Hainan Island, China. The species possesses the maximal number of prostomial appendages observed in the taxon: three antennae and one pair of palps. The body is composed of 9 segments, all of which bear cirri and compound chaetae. With the exception of one species it differs from hitherto known nerillids by the presence of two cirri on the parapodia of segments 2 to 9. This most disparate character is considered to be primitive for the family Nerillidae: it is the decisive diagnostic character of the new genus, which now also includes Leptonerilla prospera (Sterrer & Iliffe 1982).