Molecular phylogeny of interstitial Polycopidae ostracods (Crustacea) and descriptions of a new genus and four new species

Abstract

Family Polycopidae is one of the more abundant and diverse taxa occurring in marine interstitial environments. Most of the interstitial polycopids are so far known from Japan and belong to the genus Parapolycope Klie, 1936. In this paper we describe another four new species from Japan. A new genus, Kliecope gen. nov. is erected to include one new species Kliecope mihoensis sp. nov. and one new combination Kliecope oligohalina (Tanaka Sz Tsukagoshi, 2010) comb. nov. Although the morphology of Kliecope is similar to Parapolycope, the new genus has the following diagnostic characters: absence of an inward bulge on the antennular second podomere, presence of two setae bearing a sucker on the antennular third podomere, and absence of a dorsal seta on the basis of mandibula. Another three Parapolycope, Parapolycope setouchiensis sp. nov., Parapolycope subtidatis sp. nov., and Parapolycope miurensis sp. nov. are described as well. To test the phylogenetic relationship between the new genus and Parapolycope, we performed playlogenetic analyses based on the 14 18S rDNA sequences of interstitial Polycopidae species, 12 of which were newly obtained from our material. The 18S gene proved to be suitable for phylogenetic analyses in polycopids with high intraspecific or intrageneric resolution. Here we present trees obtained with maximum n likelihood, maximum parsimony, and neighbour-joining methods, and they support the divergence between Kliecope and Parapolycope with high bootstrap values.