Laticauda colubrina

Laticauda colubrina
Conservation status

Least Concern  (IUCN 3.1)[1]
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Elapidae
Subfamily: Hydrophiidae
Genus: Laticauda
Species: L. colubrina
Binomial name
Laticauda colubrina
(Schneider, 1799)
Synonyms

Hydrus colubrinus Schneider, 1799
Platurus colubrinus Girard, 1858

The colubrine sea krait, banded sea krait or yellow-lipped sea krait (Laticauda colubrina) is a species of sea snake found in tropical Indo-Pacific oceanic waters.

Description

See snake scales for terms used

Ventrals are large, one-third to more than half the width of the body; nostrils are lateral; nasals are separated by internasals; 21-25 longitudinal rows of imbricate scales are found at midbody; an azygous prefrontal shield is usually present; and the rostral is undivided.

The body is subcylindrical, only slightly compressed. The rostral is higher than broad; an azygous shield separates the prefrontals, but sometimes is absent; the frontal is considerably longer than its distance from the end of the snout; one preocular and two postoculars are present; with 7-8 supralabials, the 3rd-4th touch the eye temporals 1+2 ; five infralabials are in contact with the genials, both pairs of which are usually well developed and in contact with one another, the anterior pair is smaller than the posterior; a double series of elongated scales, the inner series the larger, occur at the oral margin. Scales are in 21-23 rows (rarely 25). Ventrals number 213 to 245, and are about four times as long as broad. Subcaudals in males number 37-47, and in females 29-35.[2]

The yellow snout and paddle-like tail of L. colubrina, Zamboanguita, Philippines
The yellow snout and paddle-like tail of L. colubrina, Zamboanguita, Philippines

Total length: males 875 mm, females 1420 mm; tail length: males 130 mm, females 145 mm. In colour these snakes are light or dark bluish grey above, yellowish below, with black bands more or less of uniform width throughout or narrowing on the belly (some of them interrupted below). Upper lip yellow. Snout yellow, the colour extending backward on each side of the head on each side of the head above the eye as far as the temporal shields, leaving a dark bar in between. Rest of the head is black. They are venomous but are not aggressive to divers.

Biology

Banded sea kraits are often seen in large numbers in the company of hunting parties of giant trevally (Caranx ignobilis) and goatfish. Their cooperative hunting technique is similar to that of the moray eel, with the kraits flushing out prey from narrow crevices and holes. Kraits need to drink fresh water and regularly come onto land for that purpose.

While probing crevices with their head and thus unable to observe approaching predators, banded sea kraits can fool their potential enemies to believe that their tail is the head. This is based on both colouration and tail movements, such that the lateral aspect of tail corresponds to the dorsal view of the head.[3][4]

Observation and nesting

Banded sea kraits rest and nest on rocky headlands and beaches of Sabah, Borneo. They can be seen in the wild at Pulau Tiga, the tip of Borneo and Mabul Island. They are, however, seen on many other rocky headlands around Sabah that are harder to access. Occasionally, they come ashore at Tanjung Aru close to Kota Kinabalu. They can be seen in captivity at The Green Connection, an aquarium in Kota Kinabalu.

The males come ashore early in the evening and wait at the high tide line for the females. Females are much larger and many males will escort and intertwine around a single female.

There are fewer recorded bites from this species compared to other poisonous species such as cobras and vipers as it is less aggressive and tends to avoid humans.[5] If they bite, it is usually in self-defence when accidentally grabbed.[6] Many fishermen are bitten each year when they try to clear sea snakes from their nets.[7]

Distribution

Banded sea krait is a widespread species in eastern Indian Ocean and Western Pacific. It is found from eastern coast of India east through coasts of SE Asia to Malay Archipelago and to southern China, Taiwan, and the Ryukyu Islands of Japan. Vagrant individuals have been recorded in Australia, New Caledonia, and New Zealand.[1]

Parasites

Banded sea kraits when collected near the tip of Borneo had heavy tick infections.[8]

See also

References

  1. 1.0 1.1 Lane, A., Guinea, M., Gatus, J. & Lobo, A. (2010). "Laticauda colubrina". IUCN Red List of Threatened Species. Version 2012.1. International Union for Conservation of Nature. Retrieved 7 October 2012.
  2. Smith, M.A. (1943). The Fauna of British India, Ceylon and Burma, Including the Whole of the Indo-Chinese Sub-Region. Reptilia and Amphibia. 3 (Serpentes). London: Taylor and Francis. p. 443.
  3. Rasmussen, A. R.; Elmberg, J. (2009). "`€˜Head for my tail´€™: A new hypothesis to explain how venomous sea snakes avoid becoming prey". Marine Ecology 30 (4): 385–390. doi:10.1111/j.1439-0485.2009.00318.x.
  4. "Sea snake's two-headed illusion". BBC News. 6 August 2009. Retrieved 7 October 2012.
  5. "Laticauda colubrina Colubrine or yellow-lipped sea krait". Animal Diversity Web (University of Michigan Museum of Zoology).
  6. Karleskint, George; Small, James; Turner, Richard (2009). "Introduction to Marine Biology". Cengage Learning. p. 307. ISBN 9780495561972.
  7. ClickLaXem (2012-07-11). "National Geographic Wild - Deadly Snakes". YouTube. Retrieved 2014-08-20.
  8. Clark M & S Oakley (2011) Tick parasites on the sea snake Laticauda colubrina. Popular account at: http://tracc-borneo.org/2011/03/sea-snake-parasites-1/, referenced May 2011.


Further reading

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