A Systematic Study on the Order Leptostraca (Crustacea: Malacostraca) from South KOrea

초록

This research presents a taxonomic study of Leptostraca from South Korea from 2011 to 2014. The order Leptostraca is the only extant order in the subclass Phyllocarida and is considered by many researchers to be the most primitive group in the class Malacostraca. This taxon includes 59 species (including subspecies) belonging to 10 genera in three families. As a result of the morphological study, four leptostracan species belonging to two genera are identified and classified, of which three species turned out to be new species: Nebalia koreana n. sp.; Nebalia pseudotroncosoi n. sp.; and Nebalia dolsandoensis n. sp. One species are new to Korean fauna: Parenebalia longipes (Willemoes–Suhm, 1875). New species and new record in Korea are described and illustrated in detail. These four species are recorded in Korea for the first time. The world distributions of Nebalia and Paranebalia species are provided in this study. In addition, we discuss sexual dimorphism in the genus Nebalia and propose the necessity of describing male traits when reporting new species. As a result of the molecular study, 428 bp mitochondrial cytochrome c oxidase subunit 1 (mt CO1) gene sequences are determined from 25 individuals of three species of Nebalia, collected from Korea. In addition, 24 CO1 sequences of four species (Nebalia hessleri Martin, Vetter & Cash–Clark, 1996, Nebalia gerkenae Haney & Martin, 2000, Nebalia kensleyi Haney & Martin, 2005, and Dahlella caldariensis Hessler, 1984) which retrieved from NCBI databases are also used in the analyses. The sequence is consisting of a 1–34% difference on closely related species, and it is also large enough to designate these nebalian species as a different species from other one. This study confirms the usefulness of molecular techniques for biodiversity and phylogenetic relationship studies of Leptostraca