Structure and distribution of mussels of the genera Musculus and Vilasina (Bivalvia, Mytilidae) in coastal areas of the eastern Kamchatka Peninsula and adjacent islands [Russian]

摘要

The data on 188 macrobenthic samples, which were collected on the coast of the southeastern Kamchatka Peninsula and adjacent islands, allowed us to find that four species of the genera Musculus (M. minutus and M.filatovae) and Vilasina (V. vernicosa and V. pseudovernicosa) inhabit together only the continental coast, while 1-3 species occur on the islands. In different years, the mollusks may disappear on one areas and appear on other ones. The relationships between the density of mollusk populations and type of ground are revealed. The density of V, pseudovernicosa is lower in the areas where this species live together with V. vernicosa. Four types of age structures differing in the presence/absence of one of the age groups were distinguished independently of the species status. The type of age structure of mollusk population within a particular region is determined by their annual recruitment. Within the range of each region, juveniles are distributed by small patches resulting in the predominance of various age groups in the age structure of different, sometimes adjacent settlements.