Hydrophis gracilis

The graceful small-headed sea snake or slender sea snake ("Hydrophis gracilis") is a species of Elapidae (Hydrophiinae-sea snake). "Microcephalophis gracilis" is a synonym of the snake.
Diagnostic characters.
Head small, body long and slender anteriorly; scales on thickest part of body juxtaposed; 5-6 maxillary teeth behind fangs; 17-21 scale rows around neck, 30-36 around thickest part of body (increase from neck to midbody 18-24); ventrals divided by a longitudinal fissure; prefrontal in contact with third upper labial; ventrals 220-287.
Total length males 950 mm, females 1025 mm; tail length males 80 mm, females 95 mm.