THE BEHAVIOR OF PAGURIDS IN SYMBIOTIC ASSOCIATIONS WITH ACTINIANS IN JAPAN

Abstract

Six Japanese species of symbiotic pagurids (5 Dardanus spp. and Diogenes edwardsi) displayed active behavior patterns towards their symbiotic actinians. Amongst these: pagurids which were freshly collected, 5 species of nonsymbiotic pagurids, including one species of Dardanus, showed no activity towards anemones. It was noted that Dardanus spp. in placing Calliactis polypus on their shells, locates the first anemone to the right and the second to the left of the shell aperture. D. edwardsi showed two different behavior patterns: it always placed S. paguri on the claw and never on the shell; it placed other anemones only on the shell and never on the claw. Symbiotic pagurids, when brought into contact with nonsymbiotic actinians, were either indifferent or they broke off contact after displaying activity for a short period only.