
Photo: (c) Hugo Innes, some rights reserved (CC BY) · CC BY 4.0
Hydrophis stokesii
Rare visitor: recorded only occasionally in this country
Stokes's Sea Snake (Hydrophis stokesii) is a large sea snake with a laterally compressed swimming tail and a stout marine body, sometimes placed in the separate genus Astrotia. Identification should combine documented pattern, scalation, body form and locality because related Japanese reptiles may be very similar. Claims here are limited to the opened species accounts (Wikipedia, general species account; Reptile Database).
It is endemic to tropical Indo-Pacific oceanic waters and is an elapid; the opened account provides limited species-level feeding and reproductive information, so those topics are omitted. Information absent from those species-level sources is omitted rather than inferred from relatives. Japanese occurrence follows the site's catalogue and the opened distribution accounts (Wikipedia, general species account; Reptile Database). This conservative treatment keeps unresolved parts of its natural history clearly visible to readers.