One new Sclerochilus (Praesclerochilus) Sars (Ostracoda) species from Korea

Abstract

Sclerochilus Sars, 1866 is the most diverse genus of the family Bythocytheridae, one of the longest surviving groups of extant ostracods, and the oldest representative of the superfamily Cytheroidea. It has a worldwide distribution at various marine depths, and it includes three subgenera: Fascichilus Schornikov, 1981; Praesclerochilus Schornikov, 1981; and Sclerochilus Sars, 1866. We describe Sclerochilus (Praesclerochilus) jejuensis sp. nov. from Jeju Island, South Korea, raising the number of known Praesclerochilus species to 13. Although most species belonging to this subgenus have very similar carapace shape, the new species differs morphologically from its most similar congeners, S. (P.) mukaishimensis Okubo, 1977; S. (P.) pruniformis Schornikov, 1981; and S. (P.) ochotensis Schornikov, 1981, by the large ventral process on the hemipenis. So far, 29 Sclerochilus species have been reported from South Korea, only one of which was named, but for which no descriptive information was provided. Therefore, this is the first taxonomic report of a Sclerochilus species from South Korea.