A New Species of Cipangocharax (Caenogastropoda: Cyclophoridae: Alycaeinae) from Tokushima Prefecture, Japan

Abstract

A new alycaeine species, Cipangocharax ananensis n. sp., is described based on specimens collected from calcareous areas in Anan City, Tokushima Prefecture, Japan. Among five Cipangocharax species, the new species closely resembles C. biexcisus and C. kiuchii. However, the new species is distinguished from these two species by having a relatively larger shell, a more expanded and broader aperture with its posterior part depressed by the slightly deflected outer lip margin, the parietal lip adherent to the body whorl, and a thick calcareous operculum with a small papilla. This discovery represents the third Cipangocharax species that is found only in Tokushima Prefecture.