Review of the Capitellidae (Annelida, Polychaeta) from the Eastern Tropical Pacific region, with notes on selected species

Two new species of Notodasus Fauchald, 1972 (Annelida: Capitellidae) from the Central Indo-Pacific region

Notodasus Fauchald, 1972 is a small genus of the polychaete family Capitellidae, including 10 described species worldwide. The genus is unusual in the Central Indo-Pacific, and there is no taxonomic record of Notodasus in this region. In this study, two new species of Notodasus are described and illustrated, namely Notodasus celebensis sp. nov. and N. chinensis sp. nov. The former species, collected from the mixed-species seagrass beds in the Indonesian island of Sulawesi, is mainly characterized by the longitudinally striated epithelium on thoracic segments and the completely separated notopodial lobes. The latter species, obtained from coastal waters off southern China, differs from its congeners with the following characters: tessellated epithelium present on anterior thorax as well as on the dorsum of chaetigers 11 and 12, notopodial lobes fused and chaetal fascicles almost touching each other on anterior abdomen, and branchial pores evident from anterior abdomen. Comparisons are made with closely related species in this paper, and a revised key is provided to all described Notodasus species. The descriptions of the two new species represent the first record of Notodasus in this region and expand the geographical distribution of the genus.

Molecular Phylogeny of the Family Capitellidae (Annelida)

Capitellids have emerged as monophyletic in most but not all recent molecular phylogenies, indicating that more extensive taxon sampling is necessary. In addition, monophyly of most or all capitellid genera was questionable, as some diagnostic characters vary ontogenetically within individuals. We tested the monophyly of Capitellidae and eight capitellid genera using phylogenetic analyses of combined 18S, 28S, H3, and COI gene sequences from 36 putative capitellid species. In our trees, Capitellidae formed a monophyletic sister group to Echiura, and Capitella was also monophyletic, separated by a long branch from other capitellids. Well-supported clades each containing representatives of different genera, or containing a subset of species within a genus, indicated that Barantolla, Heteromastus, and Notomastus are likely not monophyletic. We mapped three morphological characters traditionally used to define capitellid genera (head width relative to width of first segment, number of thoracic segments, and number of segments with capillary chaetae) onto our tree. While Capitella showed unique character states, states in the other genera were decidedly not phylogenetically informative. Morphology-based capitellid taxonomy will require a fine-scale reevaluation of character states and detection of new characters.

Relocation of Dodecaseta McCammon & Stull, 1978 (Annelida, Capitellidae) in Notodasus Fauchald, 1972

The capitellid polychaete genus Dodecaseta McCammon & Stull, 1978 is relocated in Notodasus Fauchald, 1972. Two species are redescribed based on examination of type material and three new combinations are proposed: Notodasusoraria (McCammon & Stull, 1978), N.eibyejacobseni (Green, 2002). N.fauchaldi (Green, 2002). N.kristiani (García-Garza et al., 2009), is synonymized under N.oraria. Some comments on Dasybranchuslumbricoides Grube, 1878 are included.

A new species of Leiochrides from the Korean subtidal waters with notes on the taxonomic status of the genus Pseudomastus (Annelida, Capitellidae)

Leiochridesyokjidoensissp. n., collected from the sublittoral muddy bottom in southern Korea, is described as a new species. The taxonomic status of the monospecific genus Pseudomastus has been a subject of controversy for many years, as its characteristics overlap those given in recent generic definitions of Leiochrides. The results of a comprehensive review and comparison regarding the two genera, based on previous records showed minor differences. In this study, a detailed description of L.yokjidoensissp. n. is given and a comparison with closely related species is tabulated and discussed.The taxonomic status of Pseudomastus is discussed and the genus placed in synonymy with Leiochrides.