The Gyrinidae are water beetles with very unique lifestyle - adult rapidly gyrate and whirl on surface of water hunting for prey. They are found in stagnant or slowly running water and prefer clean oxygen-rich habitats. Members of the family are characterized by the following characters: compound eyes divided completely with one pair on the dorsal surface of the head (above the water line) and another on the ventral surface of the head (below the water line); antenna short with a broad, cup-shaped scape, subtriangular pedicel and elongate but compact flagellum; meso –and metathoracic legs broadly expanded and fringed with setae for swimming.
In this paper, a taxonomic review of the Korean Gyrinidae Latreille is presented. Seven species in three genera are recognized, one of which (Gyrinus pullatus Zaitzev) is reported for the first time in South Korea. We also discovered that G. curtus Motschulsky previously recorded in Korea was misidentification of G. japonicus Sharp. Habitus photographs, keys, redescriptions, and diagnostic characters with illustrations of the species are provided. The specimens used in this study are deposited in Chungnam National University Insect Collection (CNUIC), Daejeon, Korea.