Hydrophis caerulescens

Hydrophis caerulescens, commonly known as the dwarf sea snake, is a species of venomous sea snake in the family Elapidae.[2]

Hydrophis caerulescens
Hydrophis hybrida - 1700-1880 - Print - Iconographia Zoologica - Special Collections University of Amsterdam - UBA01 IZ11800171.tif
Scientific classification edit
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Elapidae
Genus: Hydrophis
H. caerulescens
Binomial name
Hydrophis caerulescens
(Shaw, 1802)
  • Hydrus cærulescens
    Shaw, 1802
  • Hydrophis cærulescens
    - Gray, 1842
  • Polyodontognathus cærulescens - Wall, 1921
  • Aturia caerulescens
    - Welch, 1994
  • Polyodontognathus caerulescens - Kharin, 2005[1]

Geographic rangeEdit

Indian Ocean (Pakistan, India, Bangladesh, Myanmar (Burma), Thailand, W Indonesia, Malaysia), Coasts of Shandong and Guangdong (China), South China Sea, Australia (Queensland), New Caledonia/Loyalty Islands.


The dwarf sea snake is bluish or grayish blue dorsally, merging to yellowish ventrally, with 35-58 deep bluish-black crossbands. The crossbands are as wide or wider than the interspaces, well defined in younger specimens, but obscure in older specimens. The head is black, and in juveniles may also have a yellowish horseshoe-shaped mark.

Adults may attain a total length of 74 cm (2 ft 5 in).

The dorsal scales are arranged in 38-54 rows at midbody (31-43 rows on the neck). Ventrals 253–334.[3]

Each hollow poison fang is followed by a series of 14-18 solid maxillary teeth. The dorsal scales on the thickest part of the body are quadrangular or hexagonal in shape, feebly imbricate (overlapping) or juxtaposed. The ventrals are almost twice as large as the adjacent body scales.

Head very small. Anterior part of body very slender, its diameter about one third the diameter of the posterior part. Rostral broader than deep. Frontal longer than broad, shorter than its distance from the rostral, much shorter than the parietals. One preocular, and one post ocular. Two superposed anterior temporals. Seven upper labials, the third and fourth entering the eye. Chin shields very small, the posterior pair separated by scales. Ventrals distinct throughout the entire body length.[4]


  1. ^ The Reptile Database. www.reptile-database.org.
  2. ^ "Hydrophis". Integrated Taxonomic Information System. Retrieved 7 September 2007.
  3. ^ Wall, F. 1921. Ophidia Taprobanica or the Snakes of Ceylon. H.R. Cottle, Government Printer. Colombo, Ceylon. xxii + 581 pp. (Polyodontognathus cærulescens, pp. 375-380.)
  4. ^ Boulenger, G.A. 1896. Catalogue of the Snakes in the British Museum (Natural History). Volume III., Containing the Colubridæ (Opisthoglyphæ and Proteroglyphæ),... Trustees of the British Museum (Natural History). London. xiv + 727 pp., Plates I.-XXV. (Hydrophis cærulescens, pp. 275-276.)

Further readingEdit

  • Kharin, V.E. 2004 On the taxonomic status of the sea snake Hydrophis caerulescens (Shaw, 1802) (Serpentes: Hydrophiidae). Biologiya Morya (Vladivostok) 30 (3): 227-229
  • Shaw, G. 1802. General Zoology or Systematic Natural History. Vol. III., Part II. Amphibia. G. Kearsley (Thomas Davison, printer). London. vi + 313–615. (Hydrus cærulescens, p. 561.)

External linksEdit