Three marine isopods, Symmius yamaguchiensis Shimomura, 2008, Colanthura pigmentata Kensley, 1980 and Synidotea nipponensis Nunomura, 1985 are reported for the first time in South Korea. The family Chaetiliidae, and genera Symmius and Colanthura are new to South Korea. We provide descriptions of the diagnostic characteristics, illustrations of three species and their partial sequences of the mitochondrial cytochrome c oxidase subunit 1 (CO1) for molecular characteristics.

• Gi-Sik Min(Department of Biological Sciences, Inha University) Corresponding author
• Ji-Hun Song(Department of Biological Sciences, Inha University)