A new species of the genus Dulichiella (Crustacea, Amphipoda, Melitidae) from the continental shelf of the Southern Sea, Korea, with comparison to the previously recorded D. appendiculata

This study aims to discover and document amphipods from Korea, contributing to the clarification of Korean amphipod taxonomy. As part of this effort, a new species of the melitid amphipod genus Dulichiella has been collected from the Southern Sea of Korea. Previously, only one species, D. appendiculata (Say, 1818) was reported in Korea. The new species, D. tridentata sp. nov. is morphologically characterized by a distolateral crown with three teeth on palm of gnathopod 2 and by the dorsal teeth formula of pleonite 1 to urosomite 3 of 7-7-7-5-4-2. However, it can be distinguished from its congeners by several characteristics, including the number of setae of cephalic lobe; the number of ventral margin robust setae of antenna 1; the number of accessory teeth on dactyli of pereopods 3–7; the shape of the palmer corner of gnathopod 2; and the posterior serrations of epimeral plate 3. This study provides a detailed illustration and comparison of D. tridentata sp. nov. with related species, particularly D. appendiculata s.l. recorded from Korea, along with a key to Dulichiella species that possess three teeth on the distolateral crown of the propodus of gnathopod 2.