Integrative taxonomy reveals Koreoniscus as a junior synonym of Mongoloniscus (Isopoda, Agnaridae), with the description of three new species

This study employs an integrative taxonomic approach, combining morphological observations, phylogenetic analyses based on mitochondrial COI, 16S rRNA and nuclear 28S rRNA sequences, and molecular species delimitation using COI sequences, to resolve the long-standing generic delimitation dispute between the isopod genera Koreoniscus Verhoeff, 1937 and Mongoloniscus Verhoeff, 1930. The results indicate that Koreoniscus is a junior synonym of Mongoloniscus syn. nov ., with two new combinations consequently proposed: Mongoloniscus huaguoshanensis (Tang & Gui, 2000), comb. nov . and M. racovitzai (Arcangeli, 1927), comb. nov . Additionally, three new Mongoloniscus species collected from China are described here: M. beijingensis sp. nov ., M. xianensis sp. nov ., and M. arciprominens sp. nov . This study clarifies the taxonomic confusion between the two genera and refines the generic system of the family Agnaridae (Isopoda).