Snakes of Sri Lanka - 11
----The Friday' News Paper
By Jayasri Jayakody
Yellow Bellied Sea Snake (Pelamis platurus) Badakaha Muhudu NayaThe only known pelagic specie of sea snake and the sole specie of the genus Pelamis, this snake are easily identified by its characteristic bright yellow underside which could well be an adaptation to protect it from predators for it provides adequate camouflage against the water when seen from below. This snake has a dark dorsal colouration and some may have spots on their tail. Such a colouration would come in handy while ambushing fish. It is a relatively small snake with a slender body and prominent caudal fin, which is in fact its modified tail. This snake is nearly incapable of terrestrial locomotion.
It is a very powerful swimmer but can also float. It prefer the continental shelf but and is occasionally recorded far out in the open ocean which would explain its wide distribution. This snake is capable of cutaneous respiration (directly absorbing oxygen from water) and can remain submerged for up to 3 hours. It is highly diurnal and often spends the night on the seabed. This snake is highly docile in nature and most likely to ignore fishermen who may handle it with impunity.
This specie feeds exclusively on fish. It ambushes its prey which it kills relatively quickly using its highly potent venom.
This snake is viviparous. The brood size is small and within the range of 2 to 10. It does not seem to have a definite breeding season and its reproductive habits vary along its wide distribution. Apparently those that inhabit Sri Lankan waters tend to give birth between January and March when the seas are calm during the inter monsoon phase. The gestation period of these snakes is uncertain and most possibly in the area of 5 to 6 months.
Upon birth, neonates measure between 220-260mm. This snake grows to a maximum length of around 100cm and reaches sexual maturity when over 60cm long.
The lethal venom possessed by this snake is capable of killing a human being within 2 hours.
The venom is neurotoxic yet only a handful of fatalities have been attributed to this snake.
Unfortunately in Sri Lanka specimens that get accidentally caught in fishing nets are occasionally sold as “exotic eels.” There have been cases where people have died after consuming flesh and foetuses of this snake.
This snake can be identified at a glance due to its unique and distinct yellow ventral colouration. Found in the Indian Ocean, Australia, New Zealand, and northern Pacific Ocean from Japan to the western coast of North America. It is an abundant specie with a low risk designation.
A fairly common specie in Sri Lankan waters, often found around the continental shelf. May venture close to the beaches where it often gets caught in fishing nets.
A small snake with a slender body and elongated, sharp snout, the Buff-Striped Keelback’s body is often light brown or buff with darker stripes. Its underside is greenish brown or pale brown and head uniformly light brown. The colour of this snake may vary from greenish brown to olive brown. Its slender body is well equipped for high speed movements which it requires during hunting and evasive action while its colouration gives it superb camouflage.
This snake is reputed as one of the most inoffensive of snakes. Many of its local names convey its innocent nature. Often it is referred by the locals as the “the snake that cannot kill” in their native tongues. This snake is diurnal by nature but may hunt at night if highly rewarding. Often frequenting near puddles and areas where frogs take refuge but very rarely enters the water itself. Humans frequently come in contact with this snake and in response it will dart out of danger and hide itself in neighbouring vegetation. If captured it will make no attempt to escape and will not attack even if viciously molested.
This snake feeds almost entirely on frogs. Its preference for frogs is due to the fact that unlike mammals frogs put up little or no resistance once captured. However this snake itself is preyed upon by many larger and fierce snakes, due to its small size and inoffensive nature.
The reproductive habits of this snake vary considerably due to its wide distribution. Mating takes place during the hot months prior to the monsoonal rains during which the snake reduces its amount of activity. In most areas this is between April and June and in Sri Lanka it is between February and May. As soon as the frequency of showers increases and the sporadic showers intensify these snakes emerge from their hiding places in their thousands. The eggs develop within the females for around two months and are ready for discharge by August. The clutch is usually between 4 and 10 but females are capable of producing up to 14 eggs. The female incubates the eggs for another 30 to 35 days until hatching.
Hatchlings of this specie on average measure 150mm. These snakes immediately start to feed on large insects, lizards and earthworms and are in turn preyed upon by large frogs, birds and other reptiles. Those that manage to survive their first year double their length. During the second year of life these snakes continue to grow at a rapid rate and reach sexual maturity when they are three years old. By then they measure on average 45-50cm. Females are generally longer than males. The longest males seldom exceed 55cm while females often reach 60cm or more with occasional lengths of 70cm. This snake is non-venomous.
The lateral light brown or buff stripes which run along the entire body length of this specie often give away its identity at a distance. Its comparatively large eyes are also a good indicator.
Distributed in South Asia, South East Asia, Southern China and Taiwan.
A common and ubiquitous snake in Sri Lanka with a near island wide distribution except for the extreme north and highest peaks of the central hills. It is commonly found around paddy fields, cultivated areas and marshes. If an area has a healthy population of frogs the chances are that there is an equally healthy population of this snake. This snake is becoming exceedingly rare in urbanized areas and fails to thrive in such places most possibly due to lack of suitable prey.