Sea snakes are venomous reptiles that live most or all of their lives in the sea. They’re so adapted to life in the ocean that few species can crawl on land. They swim like eels with their paddle-like tail and laterally compressed body. Like marine mammals, they lack gills and must come to the surface to breathe.
Sea-snakes are cold-blooded reptiles, so they live mostly in warm tropical waters, like the Gili Islands. During the diving around the Gilis you will meet some Sea snakes. Sea snakes are fully adapted to breathe, feed, breed and grow in the sea. For air-breathing animals, sea-snakes are remarkable divers. Some species can dive to 100 metres or more, and remain submerged for up to 80 minutes. This may be partly due to the remarkable ability of some species to absorb part of the oxygen they need through their skins. Their nostrils have valves that close when they are under the water.
Sea snakes inject venom with their bites to subdue and kill prey, which is then grabbed in the jaws and swallowed whole. As with other snakes, the skullbones of sea-snakes are loosely attached and they can dislocate their lower jaws and slide them sideways to allowing them to swallow very large prey. Sea-snakes tend to be fussy eaters. Some only eat catfish, another only eats the eggs of two families of fish. Others dine on eels, fish, prawns, crabs and worms.
Sea snake venom is among the most venomous of all snakes, yet sea snakes rarely inject enough venom to significantly harm a person. In fact, very few human deaths from sea snakes have been reported. They prey mainly on fish and other sea creatures.
Sea snake venom has properties that may one day help in surgeries. Scientists are currently researching whether sea snake venom can be used as an anesthetic.
Female sea snakes sometimes attract attention from more than one suitor and mate in the open water. They give birth to live young at sea. The mother then leaves the young to fend for themselves.
No species of sea snakes are listed as threatened, although the distribution and status of most species is not very well known.