Pelonaia quadrivena n. sp.a case of bipolarity in Ascidiacea

摘要

A new ascidian species of the genus Pelonaia (Ascidiacea, Styelidae) is decribed from the coastal shore of Terre Adelie, Antarctic. The genus was referenced by a single species widely distributed in the arctic seas. Comparative anatomical descriptionsare given for the species of both hemispheres. The validity of the genus is confirmed. The French MNHN and IPEV program "REVOLTA" (Radiations EVOLutives en Terre Adelie) in January-February 2010 has collected and photographed benthic organisms from thecontinental shelf. The purpose was to survey the benthic fauna at depths ranging from 20 to 200m.