The gastropod-crustacean connection: towards the phylogeny and evolution of the parasitic copepod family Splanchnotrophidae

Lomanoticola nishiharai n. sp., a New Species of Copepod Parasitic on the Facelinid Nudibranch, Sakuraeolis enosimensis (Baba, 1930), from the Seto Inland Sea, Western Japan, Including Histological Observations of the Female Lateral Body Process

Splanchnotrophidae Norman and Scott, 1906 is a family of parasitic copepods that infest nudibranchian and sacoglossan sea slugs. In this study, a new species of splanchnotrophid copepod, Lomanoticola nishiharai n. sp., is described based on specimens of both sexes collected from the facelinid nudibranch, Sakuraeolis enosimensis (Baba, 1930), in the Seto Inland Sea off Hiroshima, central Japan. It represents the third species of Lomanoticola Scott and Scott, 1895 and is characterized by the following female characters: the cephalosome distinctly protruded; the second and third lateral processes on the body originated from same bases; the caudal rami bears a seta V which almost same as long as the rami. Ultrastructural observations revealed that the cuticular surface of the lateral process on the female body is covered with numerous protuberances that may have protective functions against the cellular immune system of the host.