The Pea Crab Pinnaxodes mutuensis Sakai, 1939 (Decapoda: Pinnotheridae) in a Rare Symbiosis with the Burrowing Bivalve Mollusk Panomya nipponica Nomura et Hatai, 1935

The pea crab Pinnaxodes mutuensis Sakai 1939 was found for the first time in the burrowing bivalve mollusk Panomya nipponica Nomura et Hatai, 1935 from Vladimir Bay, the continental coast of the Sea of Japan. Symbiotic relationships of this crab with the infaunal mollusks Ruditapes philippinarum (A. Adams et Reeve, 1850), Barnea manilensis (R.A. Philippi, 1847), and Mya japonica J.C. Jay, 1857 from Aniva Bay (southern Sakhalin), as well as with Panomya ampla Dall, 1898 from the coastal waters of Hokkaido, were previously known. Data on the ecology of P. mutuensis are summarized. The role of infaunal mollusks in its symbiotic life style is assumed to be more significant.