Distributed range & status
The Sri Lankan record of this species is in need of verification. These snakes are found primarily in warm tropical waters of the Indo-West Pacific. They have been recorded in the Indian Ocean, Solomon Islands, Gulf of Thailand, Philippines, Andaman Islands, Nicobar Islands, Coast of Taiwan, Bay of Bengal, coast of Malay Peninsula, Indoaustralian Archipelago to New Guinea, Japan, Australia, New Zealand, western Pacific Ocean to Fiji, New Caledonia, Mexico, El Salvador and Nicaragua. In Malaysia, they are the principal inhabitant of Kalampunian Damit or Snake Island in Sabah.
Scales
rostral |
Undivided, higher than broad. Touches other 6 scales. |
frontal |
Considerably longer than its distance from the end of the snout. Touches other 7 scales. |
supraoculars |
|
parietals |
|
prefrontals |
3 present. zygous shield separates them or may be absent |
nasals |
separated by internasals & undivided |
internasals |
present |
loreals |
|
preoculars |
1 |
postoculars |
2 |
temporals |
1+2 |
Supralabials |
7-8 (3 & 4 touches the eye) |
mental |
|
infralabials |
5 pairs present. Contact with the genials, both pairs of which are usually well developed and in contact with one another, the anterior pair smaller than the posterior; a double series of elongated scales, the inner series the larger, at the oral margin. |
sublinguals |
|
coastals |
|
ventrals |
213-245 large, one-third to more than half the width of the body |
anal |
divided |
subcaudals |
males 37-47, females 29-35 (both divided) |
.
The yellow-lipped sea krait has smooth body. 21-25 longitudinal rows of imbricate scales at midbody; an azygous prefrontal shield usually present also they are overlapped.
Characteristics
Being an amphibious snake, the yellow-lipped sea kraits have developed specialized body parts to help them suit better in both land and sea. Therefore, they retain a Body sub cylindrical, only slightly compressed body shape and have developed specialized ventral scales typical of those terrestrial snakes which aid in climbing on land and in low trees. Nostrils lateral. As sea kraits are air-breathing reptiles, they must surface to breathe. For this purpose, they have an elongate cylindrical lung that extends to almost the entire length of their body, which is very efficient for gas exchange and allows them to spend a longer period underwater. They are also able to carry out cutaneous respiration and have nostril valves that prevent air from entering the lung while they submerged. A specialized glad under the tongue is used for salt excretion to avoid excess salt accumulation. They have rounded pupils & flat tails. Hemipenis free end is divided & are spinous.
Colour
It is also referred to as Yellow-lipped Sea Krait due to yellow upper lip & also referred to as the banded sea krait due to the numerous black bands covering the body. They bear a blue or blue grey base colour and 20 to 65 black bands encircling the body. 36-50 black annuli are present & are separated by the bluish grey bands. Its ventral surface is yellow or cream. The snout & a small bar above the eye are also yellow. The head is black
Venom
They are highly venomous as they can produce 10-15 mg of venom (fatal dose only requires 1.5 mg). They are known to cause a rash on the attacked area, which consists of small little bumps. Deaths are in record but no deaths are recorded from Sri Lanka.
Dentition
Cobra-like venom fangs located at the front of the upper jaw.
Behavior
They are mostly nocturnal and usually move between land and ocean during this time though they have been spotted occasionally to hunt during the day. These snakes inhabit shallow tropical seas surrounding small coral islands, coral reefs and mangroves, usually those with a sand or coral substrate. They are found at depths ranging between 1 - 10m. This is mainly due to the low permeability of the skin which could be dangerous below these depths. These snakes are very dangerous and can kill you if you get bitten.
Fortunately, they are non aggressive. They seldom bite even in self-defense.
Breeding
This snake is a member of the only genus of oviparous sea snakes & returns to land to breed. The eggs are produced in caves on rocky islands between June to August. Large aggregations form at these breeding and resting sites. Males reach sexual maturity at about 18 months whereas females can take up to 24 months before they are ready to breed. Clutch sizes tend to be large but may vary geographically 3-13. A female can lay eggs at any time of the year.
Growth
They weigh up to 2 kg. Adult male is smaller than the female. The maximum length recorded is 3600 mm. Total lengths: males 875 mm, females 1420 mm; tail length: males 130 mm, females 145 mm.
Food
Their main diet comprises of eels but they also feed on small fish such as gobies. They trap their prey in to holes. Males being the smaller sex usually forage in shallower water than females and also tend to prey on different kinds of eels than do their mates. Males tend to take smaller, reef-flat eels whereas females prey on larger eels in water close to the reef. Although they are marine species, they have been seen drinking rainwater from puddles on ground and depressions in leaves.
Identification
The nasals of this snake are separated by internasals. In all other sea snakes the nasals touch each other.
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