Addition of the Sea Snake, Hydrophis stokesii (Reptilia: Squamata: Elapidae), to the Herpetofauna of Japan

Abstract

Hydrophis stokesii was collected in the coastal water of Okinawajima Island on 30 March 2021. This is the first record of the species from Japanese waters, extending its known range of occurrence toward east-northeast by more than 900 km. The snake was an adult female, 1,545 mm in snout-vent length, 203 mm in tail length, and 3,360 g in body mass. It had 11 well-developed yolked follicles in ovaries and a half-digested spiny puffer fish (Diodon sp.) in its stomach. This individual may possibly represent a stable population of H. stokesii in the Okinawan waters.