Banded Sea Snake (Laticauda colubrina)

By: C.M.Shorter

Banded Sea Snake

Sea Snakes are highly venomous marine reptiles inhabiting the warm tropical waters of the world. Sea Snakes have developed anatomical features streamlined for adaptation to an aquatic environment. Evolutionary marvels living at sea, Sea Snakes must still surface to breath air unlike eels, underwater neighbors who share the same habitat, like the moray eel, who have gills for absorbing oxygen and are absent of any scales. Banded Sea Snakes evolved from land species into aquatic reptiles having smooth-scaled bodies easy to recognize in shades of light blue with black bands. Excellent swimmers and divers, there are over 70 species of Sea Snakes making them one of the most plentiful and widely disbursed family of poisonous reptiles in the world. Over 50 species are members of the family Hydrophiidae. Snakes in this family typically have laterally compressed tails which they use like oars to propel themselves through the water, valvular nostrils with valve-like flaps which they close upon submersion, accompanied by total loss of ventral plates. Because they must surface to breathe, Sea Snakes are known to frequent the shallow ocean waters of beautiful tropical coral reefs of the world.
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Tropical reefs, like Australia's Great Barrier Reef is home to more than 22 varieties of Sea Snakes. Banded Sea Snakes feed primarily on the crabs, cuttlefish, eels, fish, fish eggs, and squid commonly found in the shallows of the coral reefs and estuaries surrounding coral reef habitats. Sea Snakes are not found in the Atlantic Ocean or the waters of the Caribbean. Fish migrating through the ocean waters are known to return to the shallow waters of the sea to set up "baby fish nurseries". These oceanic nurseries team with newborn life and fish eggs and are primary feeding grounds for the world's Sea Snakes. As we move up the food chain, these same ocean waters are also frequented by some of the world's largest predators, including Hammerheads, Tiger Sharks, Black-Tipped Reef Sharks and the Great White Shark.

Although aquatic dwellers well adapted to navigate their marine environment , Sea Snakes must surface periodically to breathe. Sea Snakes can stay submerged for extended periods of time with their left lung running almost the entire length of their bodies. Banded Sea snakes do not have eyelids but rather modified scales to protect their eyes. Sea Snakes shed their skin as often as every 2 to 6 weeks. This frequent shedding of their skin, much more often than land dwelling snakes, is nature's defense to help rid the Sea Snakes of parasites which attach themselves to the snake's body.

Sea Snake venom is Neurotoxic (affecting the nervous system) classified in the group Proteroglypha and sometimes Myotoxins (affecting skeletal muscles) with a fatal dose being about 1.5 milligrams. Most Sea Snakes produce an average of 10-15 mg of venom so they should always be approached with caution as this venom is 10x more lethal than the venom of the landbased Rattlesnake or Africa's deadly Black Mamba. Even a dead or decapitated Sea Snake is capable of delivering a bite reflex strike capable of producing a life threatening envenomation. Sea Snake Antivenom is available for snake bite victims or Tiger Snake Antivenom may be used as a substitute. A word of caution - a Sea Snake bite may sometimes go unnoticed due to the small size of their fangs. Sea Snakes have Fixed Front Fangs with venom designed to immobilize prey and does not produce the immediate "sting" and excruitiating pain immediately following the sting of a Jellyfish, or encounter with the deadly Blue-Ringed Octopus, a Lionfish, Reef Stonefish (the most venomous fish in the world), Scorpionfish, Sea Urchin, or a barb strike from the tail of a Stringray.

Although highly venomous, most Sea Snakes have a placid disposition. These cold-blooded sea reptiles are direct descendents of land dwelling snakes classified in the family Elapids. One now distant and highly venomous land relative in the family Elapidae is the Cobra. It is estimated that 75-80% of Sea Snake bites are "blank" non-productive bites meaning envenomation does not occur. Although known to be non-aggressive, except during mating season, only a few Sea Snake attacks on humans resulting in death have been recorded on divers who have disturbed nesting areas. Sea Snakes have a reputation for being very curious and have a fixation for any elongated floating object such as the air hoses of deep sea divers or even a snorkeler's fin. Most Sea Snake bites are recorded when fisherman fall victim to Sea Snake bites while untangling their fishing net catches. Sea Snakes also present a high degree of danger to humans particularly after tropical storms when they are washed ashore becoming virtually helpless to move and extremely dangerous alive or dead.

Viviparous, Sea Snakes bear live young offspring at sea after an extended gestation period anywhere from 4 to 11 months. Young Sea Snakes are independent at birth swimming immediately away from their mother. Only one species, the Banded Sea Krait - Laticauda colubrina is still equipped with ventral plates to navigate on land, and this species comes ashore to lay eggs. Males have two penises, named hemipenes, with only one used at each mating.

Common Name: Banded Sea Snake
Scientific Name: Laticauda colubrina
Snake Family: Elapidae
Sub-Family: Hydrophiinae ("true" Sea Snakes)
Description: Shades of Light Blue with Black bands that look like black rings running the full length of their bodies.
Characteristics: Not known to be aggressive but will defend themselves when threatened.
Reproduction: Viviparous (bearing live young) and breed from spring to fall giving birth to as many as 14 young from late summer to early fall.
Length: 75-200 centimeters (Approx. 2.5-6.5 ft)
Habitat Distribution: Common in oceanic coastal waters of Australia, New Guinea, Pacific Islands, the Philippines, Southeast Asia, Sri Lanka, Japan. Absent in the Atlantic Ocean, and the Caribbean north of Baja.
Subspecies - There are Five (5) major groups of Sea Snakes:
Hydrophiids: True Sea Snakes (54 Species) evolving 30 million years ago from terrestrial Elapids with Fixed Front Fangs.
Laticaudids: Sea Kraits (5 Species) four of which are marine. Strongly banded, common in Southeast Asia and the Pacific Islands.
Acrochordids: File Snakes (3 Species). Only one species is fully marine. Non-Venomous giving birth to live young.
Homalopsids: Mangrove Snakes evolved from the Colubridae family. Venomous but rear-fanged found in tropical Asian and northern Australian waters.
Natricids: Salt Marsh Snakes (3 Species) also evolved from the Colubridae family. Not venomous and confined to salt marsh environments in temperate and sub-tropical North America.