Two new species of Pseudocrangonyx (Amphipoda: Pseudocrangonyctidae) from the hyporheic zones in South Korea.

Pseudocrangonyx Akatsuka & Komai, 1922, is the most diverse group of subterranean amphipods in the groundwater communities of Far East Asia and is related to the biogeographic origin and evolution of subterranean amphipod fauna in the region. In this study, we describe two new subterranean species of pseudocrangonyctid amphipods, P. seomjinensis sp. nov. and P. danyangensis sp. nov., from the hyporheic zones in South Korea. These new species can be distinguished from their congeners by the length of the uropod 2 outer ramus, the number of accessory flagella of antenna 1, and telson shape. Additionally, we determined sequences of the nuclear 28S rRNA and the mitochondrial cytochrome c oxidase subunit I gene of the new species for molecular analyses.