The dangerously venomous Hydrophis spiralis occurs in Myanmar coastal waters and tidal rivers and in the Persian Gulf east to central Indonesia (Sulawesi) and north to the Philippines. Little is known about the natural history of this species, but it has been reported from deep water habitats. (Leviton et al. 2003)
Leviton et al. (2003) provide a technical description of Hydrophis spiralis: Scales on thickest part of body with rounded or pointed tips, imbricate; 6-7 maxillary teeth behind fangs; normally 1 anterior temporal; 6-8 upper labials; 25-31 scale rows around necks, 33-38 around midbody (increase from neck to midbody 4-8); ventrals 295-362, distinct throughout, about twice as broad as adjacent body scales; yellowish or yellowish green above, dorsal scales edged with black, 41-46 narrow black bands encircle body, the bands usually less than one third the width of the lighter interspaces; head in young black with yellow horseshoe-shaped marking; in adult head usually yellow. Total length: males 1620 mm, females 1830 mm; tail length males 140 mm, females 120 mm.
Sea snake envenomation of humans is not common, in large part to the generally non-aggressive nature of sea snakes, but Amarasekera et al. (1994) give a detailed medical account of a fisherman bitten by a Hydrophis spiralis.
Sanders and Gardner (2012) developed microsatellite loci for H. spiralis. These markers appear to amplify, and have useful levels of variation, in several other Hydrophis species as well, suggesting that they could be broadly useful in studies of sea snake conservation genetics.
Yellow sea snake
Persian Gulf eastward to Taiwan and Japan, the Philippines, Malaya Peninsula, Sumatra, and Borneo.
Holotype: BMNH 1946.1.6.94 (formerly BMNH iii.6.10c).
Type-locality: Unknown. Given as Indian Ocean in BMNH catalogue, and by M. A. Smith, 1943, Fauna Brit. India, Rept. Amph. 3:1-583[453]; and Stuebing, 1991, Raffles Bull. Zool. 39:323-362[356].