Abstract <p>The results of a comparative analysis of epibiotic communities of the introduced Barents Sea red king crabs are presented according to long-term studies carried out in the waters of the Dalnezelenetskaya Bay. There was a twofold increase in species richness in the period from 2004 to 2013. There was an increase in the prevalence and mean intensity of infestation. The increase in biodiversity indices is explained by the expansion of symbionts due to the appearance of both new rare epibionts and new common symbionts, in particular, copepods. Changes in the structure of epibiotic communities are associated with the ongoing adaptation of the red king crab to the conditions of the Barents Sea, and the dynamics of population indices are associated with the changes in size and age structure of the local crab population and interspecific relationships between symbionts.</p>