Marine Macrodasyida (Gastrotricha) from Hokkaido, Northern Japan

摘要

Three new species of macrodasyidan gastrotrichs are described from the coasts of Hokkaido, northern Japan. Cephalodasys mahoae sp. nov. differs from congeners in having the oocytes developing from posterior to anterior. Turbanella cuspidata sp. nov. is characterized by a pair of small, ventrolateral projective organs at U06. Turbanella lobata sp. nov. is unique among congeners in having paired lateral lobes on the neck. We inferred the phylogenetic position of C. mahoae sp. nov. by maximum-likelihood analysis and Bayesian inference based on 18S rRNA, 28S rRNA, and COI gene sequences from 28 species of macrodasyids. In the resulting trees, C. mahoae sp. nov. formed a clade with an unidentified species of Cephalodasys Remane, 1926, but not with C. turbanelloides (Boaden, 1960).