Review of the taxonomy, geographical distribution, hosts, and infestation of Athelges takanoshimensis (Isopoda: Bopyridae), an ectoparasite of hermit crabs

Abstract

Abstract: The bopyrid isopod Athelges takanoshimensis Ishii, 1914 was originally described in 1914 using specimens from Japan and has since been reported from Far Eastern Russia, Korea, China, Taiwan, Philippines, Singapore, Indonesia, and Papua New Guinea. Japan is located at the northernmost limit of the distribution of the species. This review lists all known host species from these countries and shows all collection localities on maps of Japan and East Asia. Two families of hermit crabs, Paguridae and Diogenidae, serve as hosts for A. takanoshimensis. In subarctic and temperate waters, pagurids are major hosts, but their importance decreases in subtropical waters. Diogenids are infested in subtropical and tropical waters, but the known hosts from the latter waters are only diogenids. Infested hosts are usually found in the intertidal zone but there is a record of the species collected as deep as 508–680 m. Prevalence of infestation is usually less than 10% and differs between host species. The previous work of A. takanoshimensis focused largely on its taxonomy, and we need further research to understand various aspects of the biology (e.g., host utilization, seasonal and annual change in occurrence, growth and reproduction, impact on a host) of the species.