Revision of Pseudonereis (Polychaeta, Nereididae)

A taxonomic revision of Pseudonereis (Polychaeta, Nereididae) shows that some of the described taxa are very similar in most morphological characteristics. The revision includes all ten taxa considered valid, and are redescribed from type material. Lectotypes are designated for Pseudonereis anomala Gravier, 1901, Pseudonereis noodti (Hartmann-Schroder, 1962) and Pseudonereis trimaculata Horst, 1924. The widely geographically distributed and well-known P. gallapagensis Kinberg, 1865 and P. variegata (Grube, 1857) show striking morphological resemblance to less well-known taxa with similar distribution. Paragnath variation in populations of P. anomala is discussed relating to its geographical distribution. Pseudonereis trimaculata is recorded from Australia for the first time. Taxa belonging to Pseudonereis are predominantly tropical and subtropical. A cladistic analysis using parsimony is included to test for monophyly of Pseudonereis. A monophyletic clade including all Pseudonereis taxa is given low bootstrap support. This clade is supported by the synapomorphies: presence of paragnaths in closely spaced comb-like rows on the maxillary ring on the pharynx, and presence of p-bar paragnaths in Areas II-IV and VII-VIII. Several of the included taxa share the shield-shaped paragnath in Area VI, which serves to distinguish Pseudonereis spp. from Perinereis spp. Paragnaths of the type p-bars and shield-shaped bar is described for the first time; the latter character is different from the smooth bar-shaped paragnaths in Area VI as has previously been described in these taxa. c 2007 The Linnean Society of London, Zoological Journal of the Linnean Society, 2007, 150, 145-176.