A Taxonomical study of the species of the Family Leptastacidae (Copepoda : Harpacticoida) from Korea

Abstract

During a study of benthic harpacticoid copepods from the intertidal zone of East Sea and West Sea of Korea, three new species were recognized. Before this study, the family Leptastacidae had not been recorded in Korea. The three new species belong to the genera Paraleptastacus, Cerconeotes, and one new genus. The new genus is closely related to the genera Ceroneotes, Belemnopontia, Psammastacus and Steroxiphos in the characters of antennary exopod with two distal setae, 3-segmented P1 exopod, and setal formula of P2 exopod and P3 endopod. This new genus has superficial resemblance with Stereoxiphos in the third exopodal segment of P1 exp-3 with three setae. However the new species is clearly distinguished from Ceroneotes and Stereoxiphos by the characters of non-fused caudal setae IV and V, the triangular shape of caudal rami, and the median spinous process of female P5. The new genus also differs from Belemnopontia in having only three setae on the P1 exp-3. Cerconeotes sp. 1 is similar to Cerconeotes mozambicus in the setal formula of P2-P4 exopod. However, the new species is clearly distinguished from the congener by P5 setal formula and caudal rami shape. Paraleptastacus sp. 1 is seems to be closely related to Paraleptastacus wilsoni, as it has a similar setal formula of legs. The new species shares characters of the biramous P5, and P1-P4 setal fomula, except P3 endopod, with the congener. However, the new species is clearly distinguishable from all congeners by the setal formula of the legs and caudal ramus shape.