First records of Gnathia Leach, 1814 and Tachaea Schioedte & Meinert, 1879 from South Korea, with descriptions of two new species (Isopoda, Cymothoida, Cymothooidea)

Abstract. Two new species of cymothoid isopods, Gnathiakoreanasp. n. and Tachaeakoreaensissp. n., are described from South Korea. The genera Gnathia Leach, 1814 and Tachaea Schioedte & Meinert, 1879 are recorded for the first time in South Korea. Gnathiakoreanasp. n. is distinguished from its congeners by having the smooth dorsal surface of the pereon, the strongly ridged unornamented paraocular ornamentation, the strong bifid mediofrontal process, and the serrated superior frontolateral process. Tachaeakoreaensissp. n. is distinguished from its congeners by having the expanded propodus with serrated inferior margins in pereopods 1–3, the propodus with serrated inferodistal margins in pereopods 4–7, one seta on the apical lobe of the maxilla, and ten robust setae on the posterior margin of the pleotelson.