[Phylum: Chordata] [Class: Reptilia] [Order: Squamata] [Family: Elapidae (hollow fangs)]
Several key features of banded sea kraits (scientific name Laticauda colubrina) help to distinguish them from other species of sea snakes, including the band colour and where they live.
This section contains fun facts and information about the yellow-lipped sea krait, including what they eat and why their venom is so deadly.
The species is 'semiaquatic' meaning it can switch between life on land and in shallow water environments.
But, because they do not belong with the true sea snake species, they spend a surprising amount of time away from the ocean.
Even so, the banded sea krait is an excellent swimmer and it thrives in most temperate latitudes, such as the Eastern Indo-Pacific.
But, the best places to find yellow-lipped sea krait snakes are the rocky shores and coral reefs of the Indian Ocean and Western Pacific.
Even so, scuba divers have recorded sightings of these oceanic snakes at some of the popular dive sites in India, and even further south in New Zealand.
Pro Tip: Common areas for scuba divers to find banded sea kraits are the Philippines, Japan, Southeast Asia, New Guinea, the Pacific islands, and Sri Lanka.
The physical characteristics, and unmistakable colouring of black bands, helps to differentiate these sea kraits from other species of marine snakes. Other notable features of banded sea krait snakes include:
Unlike most sea life animals and plants, the adult female kraits will often grow to lengths that are a lot longer than the males. Typically, the males can grow up to one metre long. Whereas, the females can reach lengths of almost double - up to two metres long.
Yellow-lipped sea kraits can weigh anywhere between half a kilogram (one pound) and two kilograms (4 pounds). As a result, they tend to display more agility and faster speeds in water than on dry land.
Some sea kraits exhibit a behavioural trait known as 'homing' (like sea turtles). In other words, 'philopatry' means they often return to the same beach where they were born to digest their food, to rest, and to nest.
Note: The scales on sea kraits are bigger than most of the other species and they overlap where they meet at the stomach. This feature differentiates them from the closely related, and highly venomous, New Caledonian sea krait (Laticauda saintgironsi).
The banded sea krait is a highly skilled, carnivorous predator. Even so, these active predators become vulnerable while they are hunting for their preferred food.
During the hunt, the first bite of their potent neurotoxic venom renders its prey powerless. But, when the venom takes full effect, the snake usually swallows the food in one piece (whole).
The typical feeding habits and diet for sea kraits will include:
These limbless reptiles often hunt alone. But, they will also hunt in a group, sometimes with other species. Large females will search in deeper water for big conger eels. The males tend to hunt in shallow waters for smaller prey (e.g. morays).
Pro Tip: In general, banded sea kraits use their deadly venom and predatory skills for hunting large eels. They seldom 'intentionally' attack their predators, such as shorebirds and sharks, even if they feel threatened.
In fact, many sea snakes will complete their entire lifecycle in the ocean. A typical example is the olive sea snake. But, sea kraits actually spend a lot of time out of the water.
It's difficult to determine the exact lifespan of banded sea kraits with any definitive accuracy. Nonetheless, marine biologists estimate it as being around twenty (20) years.
Here's the thing:
Sea kraits feel safe enough to digest their food on dry land. They also use terrestrial rocks to help them shed their skin, even though they are well adapted for hunting food that shelters in the crevices of coral reefs.
One thing is for sure, they need to drink freshwater to survive. So, they drink at the surface when it rains and they will crawl on the ground to seek out coastal sources of clean water.
Unlike many other sea snakes, the sea krait reproduces on land - not at sea. In general, the breeding season takes place during the warmer months (e.g. September through to December).
Male kraits gather together in groups in shallow water or along the shoreline. They wait for females to show, and then they will compete in a courtship ritual to attract the 'largest' females. This is because the large females tend to produce more offspring and larger snakelets.
And the outcome...
The males often compete for the same female. It is not uncommon to see several males twine around one female. She will eventually choose a mate and lay around ten (10) eggs per clutch.
Because this is an oviparous species, the eggs develop outside the mother's body, usually inside rocky crevices for warmth and shelter. After that, the typical incubation period for snake eggs to hatch inside the nest is around four (4) months.
The general consensus is that most sea kraits are not in any immediate danger of extinction. Even so, they are at some risk from their natural predators and from certain kinds of human activities.
For instance, fishers who use fishing nets or other traps to target ocean fish and animals, often capture the banded sea krait as by-catch. In fact, marine snakes will drown if they get trapped in boat exhaust pipes and if they remain away from water for too long.
Human development in seas and oceans (e.g. aquaculture farms, tourism) also threatens the conservation status for sea kraits. Many of the activities destroy aquatic and land habitats and pose a threat to their population.
Some predatory species will follow banded sea kraits while they hunt and attack small fishes that get scared out of the reef. But, natural predators of the yellow-lipped sea krait includes:
Note: It is rare for sea snakes to bite humans (excluding careless fishermen). But, some people in the Philippines hunt a subspecies of the banded sea krait for the skin and meat. They will smoke the meat and export it to Japan for use in irabu soup (a popular cuisine in Okinawa).
Note: The short video [2:49 seconds] contains some quick answers to questions about common venomous reptiles, sea kraits, and coral reef snakes.