Distribution – Worldwide
There are over 60 species worldwide and are found in warm, shallow coastal waters of tropical and subtropical oceans from the Persian Gulf across through South East Asia to the Western Pacific and Northern Australia. but not in the Atlantic Ocean. They are also found in mangrove swamps and other brackish water habitats.They may swim up rivers and have been reported as far as 160 km from the sea.
Only one species, the yellow-bellied sea snake, is truly pelagic and can be found thousands of kilometres from land in both the Indian and Pacific Oceans.
Distribution - Australia
At least 32 species have been found in the northen Australian waters (queensland and the Northern territory). They seem to congregate in certain areas in the region about the Swain Reefs (about 250 km east of Mackay) and the Keppel Islands (about 35 km south east from Yeppoon). Some species are also found in the southern waters off Victoria, New South Wales, Tasmania, South Australia and Western Australia. One species has been found off the Tasmanian coast.
Fertilised eggs are retained inside the mothers' oviduct until they are fully developed. .The young are born alive at sea and are independent from birth, except for those of the banded sea krait (Laticauda colubrina), which comes ashore to lay its eggs. In some species, the young are quite large - up to half as long as the mother.
Kraitsy are often found sleeping in vegetation behind beaches or in rock crevices along the shore in tropical areas.
They have short fangs (2.5-4.5mm) which can penetrate skin and they can open their small mouths wide enough to bite a table top. It is said that even a small snake can bite a man's thigh. Sea snakes can swallow a fish that is more than twice the diameter of their neck.
Most sea snake bites occur on trawlers, when the snakes are sometimes hauled in with the catch. Only a small proportion of bites are fatal to humans as it is rare for much venom to be injected
A bite results in muscle pain, tenderness and spasm. . The bite itself is not particularly painful and may go unnoticed.at the site; 30 minutes after the bite there is stiffness, muscle aches and sometimes spasms of the jaw followed by moderate to severe pain in the affected area. This is followed blurred vision, drowsiness and finally respiratory paralysis. A specific antivenin is available from the Commonwealth Serum Laboratories Ltd. No deaths have been recorded from bites in Australian waters.