The genus Lapemis is sometimes regarded as comprising two species, Lapemis curtus occurring in the Indian Ocean and Lapemis hardwickii occurring in Southeast Asia and Australasia (Cogger, 2000; Smith, 1926). However, Gritis and Voris (1990) examined the morphological variation of many individuals from representative populations throughout the geographic range of this genus and found higher levels of variation within subpopulations than between the two putative species. As such, there is likely to be only one species, Lapemis curtus, and Lapemis hardwickii is a synonym of this species. Common names of Lapemis curtus are Shaw's sea snake, short sea snake and spine-bellied sea snake.