Hediste, MALMGREN, 1867

Sato, Masanori & Nakashima, Akiyuki, 2003, A review of Asian Hediste species complex (Nereididae, Polychaeta) with descriptions of two new species and a redescription of Hediste japonica (Izuka, 1908), Zoological Journal of the Linnean Society 137 (3), pp. 403-445 : 405

GENUS HEDISTE MALMGREN, 1867

Type species: Hediste diversicolor (O. F. Müller, 1776)

Amended generic diagnosis

Eversible proboscis with conical paragnaths on both maxillary and oral rings. Four pairs of tentacular cirri; parapodia biramous except for the first 2 setigers. Notochaetae homogomph spinigers. Neurochaetae homogomph spinigers with or without heterogomph spinigers, and heterogomph falcigers with or without homogomph falcigers. One or a few thick simple chaetae present in supra-acicular fascicle in posterior neuropodia.

Remarks

The presence of simple straight chaetae in the posterior neuropodia is the most important diagnostic characteristic separating Hediste from Nereis and Neanthes . The simple chaetae were previously referred to as fused homogomph falcigers ( Fauvel, 1923; Fauchald, 1977; Hartmann-Schröder, 1996). However, in the type species, H. diversicolor , nonfused homogomph falcigers are absent, while heterogomph falcigers are present. Our observations of the Japanese Hediste species suggest that a simple chaeta originates not from a homogomph but from a heterogomph falciger as pointed out by Smith (1958), and that the simple chaeta may be produced not only by fusion between a blade and a stalk of a falciger, but also by deformation of a stalk after detachment of a blade (see below).