First record of two species of hermit crabs (Decapoda, Paguridae) from South Korea, with remarks on the associated hydrozoan, Hydrissa sodalis

Two pagurid species, Pagurus quinquelineatus Komai, 2003 and Pagurus rectidactylus Komai, Saito & Myorin, 2015, are reported from South Korea. Pagurus nigrivittatus is most similar to these two species among the congeneric species known from South Korea. The additional morphological differences between P. quinquelineatus and P. rectidactylus are provided briefly. The most distinct feature of the South Korean P. rectidactylus compared to the original description is that an associated hydrozoan, Hydrissa sodalis (Stimpson, 1858) instead of Bouillonactinia misakiensis (Iwasa, 1934) is responsible for the carcinoecia. The association of H. sodalis with other hermit crabs in South Korea was investigated.