Abstract

Three newly recorded mollusks, Pteria penguin (Bivalvia: Pteriidae), Rotaovula septemmacula (Gastropoda: Fasciolariidae), and Turrilatirus turritus (Gastropoda: Ovulidae) are described from Jeju Island, Korea. P. penguin is characterized by its large, black, wing-shaped valves. T. turritus resembles T. nagasakiensis in morphology but can be distinguished by its well-developed black axial ribs and low spire in height. R. septemmacula is notable for its kite-rhomboidal shell shape, with seven distinct thick brown spots on the dorsal surface. The genus Rotaovula C. N. Cate & Azuma, 1973 is rare worldwide, representing the first record of this genus from Korea. Diagnoses, remarks, and color plates are provided for each species. In addition, to perform molecular species identification, we compared intraspecific and interspecific genetic variation based on two mitochondrial genetic markers: the 16S rRNA gene for P. penguin and the COI gene for T. turritus. The results showed few intraspecific sequence differences, but more notable congeneric sequence differences. Maximum likelihood trees revealed that the two species are closely related to other individuals of the same species, respectively, indicating that their morphology-based species identifications are reliable.