Banded Sea Krait

The Banded Sea Krait, or Laticauda colubrina, is best known for its potent venom and striking bands around its body. This small, semi-aquatic sea krait is found in the Indo-Pacific tropical waters, often in or near the coral reefs off of small islands.

This species has several common names, including Colubrine Sea Krait, Yellow-lipped Sea Krait, or Banded Sea Snake. Despite their powerful venom, they are also known for their docile behavior.

This unique serpent has adapted to life in the ocean, spending hours submerged in search of prey. Its distinctive black and white bands serve as a silent signal in the underwater world. Join us as we explore the fascinating life of this amphibious predator, unraveling its secrets and the role it plays in the marine ecosystem.

Appearance

This species is called the Yellow-lipped Sea Krait due to its yellow snout and face. The bands referenced in its name are black and number between 20 and 65, spanning their entire body. The body itself varies in color – from creamy, to grey, to blue.

The cylindrical body shape is smaller in males and larger in females, creating sexual dimorphism. Males reach up to three feet, and females reach up to four and a half feet. This small sea snake ranges from one to four pounds. This species has a long tail with a paddle-like shape, making it well-adapted for swimming.

The head is relatively small compared to the body, with a slightly flattened shape. Their tail is laterally compressed and paddle-shaped, aiding in propulsion while swimming. Their nostrils possess valves that can close, preventing water from entering during dives. The eyes are positioned slightly on top of the head, providing a wider field of vision.

While highly venomous, the krait’s fangs are relatively short and fixed, located at the front of the upper jaw.

Special adaptations

They have a special adaptation called a saccular lung, a special extension of the lungs to allow for expanded capacity. They use this feature while hunting for eels, allowing them to dive to almost 200 feet.

On land, these sea snakes are skilled tree climbers, especially in mangrove areas. They have been found up to 130 feet high in the trees.

This species also has a behavior called philopatry, where, like sea turtles, they return to the same beach year after year to breed, lay eggs, digest their prey, and rest.

Habitat

The Banded Sea Krait population originated in Papua New Guinea and has become widespread throughout Asia, the Philippines, India, the western Pacific islands, New Zealand, the Indian Ocean, and parts of Japan.

The species prefers to stay close to mangrove swamps and rocky coral reefs near the shoreline. Juveniles stay closer to shore, but as they age, they utilize the deeper and more open waters of their range, using the movements of their paddle-like tail to help them swim and maneuver in the small crevices while hunting or resting.

This small sea snake spends most of its time in the water but is known to be semiaquatic, spending some of its time on land. Adult males hunt in shallow water, typically closer to the shore. Adult females are larger and better adapted to hunt in much deeper water, up to almost 200 feet, giving them a wider hunting range.

The males and females have a unique characteristic of returning to land after hunting to digest their food in the sand or near the rocky shores.

Diet 

The carnivore is adapted to feed on prey much larger than itself. First, they use their venomous fangs to inject their prey into paralysis; then, their wide jaws consume them whole. This snake almost primarily eats eels.

The female Banded sea krait are known to dive to deeper depths to catch and eat larger Conger Eels, often three times their own body size. The males are known to hunt in shallower water and feed upon smaller moray eels.

Aside from eels, this sea snake is known to hunt small fish. They use their small heads and have been known to hunt with their own species, Giant Trevally and Goatfish. They work together to chase smaller fish out of the small crevices among the coral reefs. The sea snakes eat the smaller fish, and their hunting partners eat the larger fish.

Reproduction

They mate during the warmer months of September through December. This species has a polyandrous mating behavior, meaning the females have more than one partner during the breeding season. They undergo internal fertilization. During mating season, males gather in groups either on land or very near shore, awaiting a female.

Males reach sexual maturity at about 18 months and females from 18-24 months.

Females release a pheromone to alert their presence and willingness to breed. Once she is detected, courtship begins with males chasing a single female, intertwining with her in competition.

Once breeding has taken place, the female with lay a clutch of about 10 eggs, returning to land to nest her eggs in crevices along the shoreline. This sea krait is oviparous. After an incubation period of four months, the juvenile kraits then make their way to the shallow waters of the coral islands and shores.

Threats 

The Banded Sea Krait is susceptible to habitat loss of their aquatic coral reefs and terrestrial lands they use to live and breed. In some places in the Philippines, the species is hunted for its skin and meat.

The list of ocean and land predators is short due to their highly toxic venom. They are eaten by sharks and larger fish while they are hunting and are vulnerable themselves. They are also prey items for birds while on land and sea eagles while in the ocean.

6 More Fantastic Facts about the Banded Sea Krait

1. They hunt in the ocean but return to shore to rest, digest, and reproduce.
2. They can hold their breath for long periods of time, and they have a paddle-like tail that improves their swimming ability.
3.  Bites typically occur only when the snake feels threatened or mishandled.
4.  Their venom is among the most potent of all snakes, containing neurotoxins that can paralyze prey and deter predators.
5. Unlike most reptiles that lay eggs, sea kraits give birth to live young.
6.  In captivity, banded sea kraits have been known to live for over 10 years.

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