Spine-bellied sea snake

The specific name, hardwickii, is in honor of English naturalist Thomas Hardwicke.[2]

H. hardwickii has the following characteristics.

• Body short, stout, neck region not less than half as thick at midbody;
• head large; scales squarish or hexagonal, juxtaposed, outer 3-4 rows larger than others, scale rows: males 23-31 around neck, females 27-35, around midbody, males 25-27, females 33-41;
• ventrals small, usually distinct anteriorly, not so posteriorly, in males 114-186, in females 141-230; head shields entire, parietals occasionally divided;
• nostrils superior, nasals in contact with one another;
• prefrontal usually in contact with second upper labial;
• 7-8 upper labials, 3-4 bordering eye; 1 pre- and 1-2 postoculars; 2, rarely 3, anterior temporals; greenish or yellow- olive above, whitish below, 35-50 olive to dark gray dorsal bars, tapering to a point laterally, occasionally encircling body, a narrow dark ventral stripe or broad irregular band occasionally present;
• adults often lack any pattern and are uniform olive to dark gray;
• head pale olive to black, yellow markings on snout present or not. Total length 860 mm (2' 4"), tail length 85 mm (3.3").

H. hardwickii is located in warm waters:

• Persian Gulf (United Arab Emirates, Iran)
• Indian Ocean (Bangladesh, Burma, Pakistan, Sri Lanka, India)
• South China Sea north to the coasts of Fujian and Shandong
• Strait of Taiwan
• Indoaustralian Archipelago
• North coast of Australia (Northern Territory, Queensland, Western Australia)
• Philippines, Cambodia.[3]
• Pacific Ocean (Thailand, Indonesia, China, Japan, Papua New Guinea)

• Boulenger GA (1896). Catalogue of the Snakes in the British Museum (Natural History). Volume III., Containing the Colubridæ (Opisthogylyphæ and Proteroglyphæ) ... London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiv + 727 pp. + Plates I-XXV. (Enhydris hardwickii, p. 301).
• Gray JE (1835). Illustrations of Indian Zoology, chiefly selected from the collection of Major - General Hardwicke. Vol. 2. London (1833-1834): 263 pp., 95 plates. (Lapemis hardwickii, new species, Plate 87, Figure 2).
• Gray JE (1843). "Description of two new species of reptiles from the collection made during the voyages of H.M.S. Sulphur." Ann. Mag. Nat. Hist. [First Series] 11: 46.
• Gritis P, Voris HK (1990). "Variability and significance of parietal and ventral scales in the marine snakes of the genus Lapemis (Serpentes: Hydrophiidae), with comments on the occurrence of spiny scales in the genus." Fieldiana Zool., New Series (56): i-iii + 1-13.
• Günther ACLG (1864). The Reptiles of British India. London: The Ray Society. (Taylor and Francis, printers). xxvii + 452 pp. + Plates I-XXVI. (Hydrophis hardwickii, p. 380 + Plate XXV, figure W).
• Leviton AE, Wogan GOU, Koo MS, Zug GR, Lucas RS, Vindum JV (2003). "The Dangerously Venomous Snakes of Myanmar: Illustrated Checklist with Keys". Proc. California Acad. Sci. 54 (24): 407-462. (Lapemis hardwickii, p. 436).
• Smith MA (1943). The Fauna of British India, Ceylon and Burma, Including the Whole of the Indo-Chinese Sub-region. Reptilia and Amphibia. Vol. III.—Serpentes. London: Secretary of State for India. (Taylor and Francis, printers). xii + 583 pp. (Lapemis hardwickii, pp. 468–470, Figures 148 & 149).

• SnakeDatabase (http://snakedatabase.org/species/Hydrophis/hardwickii).