The species composition and ecological features of pea crabs of the genus Pinnixa White, 1846 (Brachyura: Pinnotheridae) in Peter the Great Bay, the Sea of Japan

Abstract

This paper provides an overview of pea crabs of the genus Pinnixa White, 1846 (Brachyura: Pinnotheridae) that occur along the Russian coast of the Sea of Japan. Three species of the genus have been recorded for this area: P. tumida Stimpson, 1858, P. rathbuni Sakai, 1934, as well as P. banzu Komai, Nishi & Taru, 2014, which is the first record for the fauna of Russia. All species clearly differ ecologically: P. tumida was found in Posyet Bay in the intestine of the burrowing holothurian Paracaudina chilensis (Müller, 1850); P. rathbuni, in burrows of the echiuroid Urechis unicinctus (von Drasche, 1881); and P. banzu, in tubes of the polychaete Chaetopterus cautus Marenzeller, 1879. The paper also provides a definitive key to Pinnixa species and data on the size, behavior, symbionts, and parasites of P. rathbuni and P. banzu.