Taxonomic Study of the Kinorhyncha in Japan -I. Pycnophyes tubuliferus Adrianov, 1989 (Kinorhyncha : Homalorhagida) from Japan

Abstract

A pycnophyid kinorhynch, Pycnophyes tubuliferus Adrianov, 1989, collected from muddy sediment at Tanabe Bay, Honshu Island, Japan is re-described and illustrated. This is the first record of the order Homalorhagida and the genus Pycnophyes from Japanese waters, and the fourth genus of the class Kinorhyncha from Japan. Previously P. tubuliferus was found only in a few localities alongside the Russian and Korean coasts in the western part of the Sea of Japan, and this is the first finding of this species outside the Sea of Japan. Detailed morphology of the species has been studied using Nomarsky microscopy and SEM for the first time. Basic taxonomic characters were compared from zoogeographic points of view among specimens representing populations from the Sea of Japan (including typematerial) and the Pacific coast of the mainland of Japan. The new diagnosis of the species has been proposed.