BIOLOGIYA MORYA, 2016, Vol. 42, No. 6, pp. 458-464

Species composition and pattern of distribution of hermit crabs (Decapoda: Paguroidea) in Vostok Bay, the Sea of Japan

© 2016 N. I. Selin, E. S. Kornienko, O. M. Korn

A.V. Zhirmunsky Institute of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok 690041

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Species composition, abundance, and vertical distribution of hermit crabs (Decapoda: Paguroidea) were investigated in Vostok Bay, the Sea of Japan, from September 2014 to September 2015. A total of seven species from two families were found in a monitoring area of about 5000 m² located on the bottom within a depth range of 0-11 m: Pagurus minutus, P. proximus, P. brachiomastus, P. pectinatus, P. ochotensis, P. middendorffii (Paguridae), and Areopaguristes hirsutimanus (Diogenidae). Their population density varied from 22 ± 13 to 26 ± 2 ind./m²; the biomass, from 55.76 ± 26.10 to 93.38 ± 27.00 g/m². The species composition remained unchanged throughout the study period. The proportions of species abundance changed between seasons, as this parameter is largely determined by seasonal migrations of hermit crabs. Pagurus minutus predominated in number in winter and spring (up to 71%); P. proximus, in summer and autumn (up to 47%). In autumn and spring, P. ochotensis and P. pectinatus constituted a major part of biomass (18-25% and 19-20%, respectively). The proportion of a previously abundant species, P. middendorffii, was very small (no larger than 1.3%) during the study period. Another four species of hermit crabs occurred in other parts of Vostok Bay; thus, the fauna of the bay currently includes 11 species of this group.

Key words: Decapoda, hermit crabs, species composition, abundance, distribution, Peter the Great Bay, Sea of Japan.