Two new species of the genus Paradexamine (Crustacea, Amphipoda, Dexaminidae) from Korean Waters

Abstract

Two dexaminid amphipod species belonging to the genus Paradexamine were collected from Korean waters. After observation and identification compared with related congeners, these two species are revealed to be new to science. In comparative identification, one of the new species, P. acutasp. nov. is similar to P. houtete in having an acutely rounded lobe and posteroventrally pointed coxa 7. However, this new species is distinguished from P. houtete in having a larger number of medial setae on the propodus of gnathopod 1 and a rounded basis of pereopod 6. This new species is also very similar to P. marlie s.l. Hirayama from Japanese waters, and P. marlie s.l. might be re-established or synonymized with P. acutasp. nov. in the future. The other new species, P. rotundogenasp. nov. is similar to P. tafunsaka in having a rounded eye lobe; however, it is distinguished from P. tafunsaka in having an elongate carpus on gnathopod 2 and the differently shaped basis of pereopod 7. A key to the five Korean species of Paradexamine, including the two new species, is also provided.