Marine REPTILES

1. Marine REPTILES Sea Snakes

2. Present-day diversity of marine reptiles in the seas is low. One reason for this appears to be that modern reptilian kidneys cannot tolerate high salinities

4. and thus the only reptiles that have adapted to marine environments are those which have developed specialized salt-excreting glands.

5. The most thoroughly marine reptiles are undoubtedly the sea snakes in the subfamily Hydrophiinae. These spend their entire lives in the sea, giving birth to live young there.

7. Sea snakes are air breathers probably descended from a family of Australian land snakes. They inhabit the tropical waters of the Indo-Pacific and are highly venomous. Thirty-two species have been identified in the waters about the Barrier Reef in Australia. The olive sea snake (Aipysurus laevis) is a familiar sight.

9. Sea snakes have specialized flattened tails for swimming and have valves over their nostrils which are closed underwater. They differ from eels in that they don't have gill slits and have scales. Due to their need to breathe air, they are usually found in shallow water where they swim about the bottom feeding on fish, fish eggs and eels.

11. The yellow-bellied sea snake ( Pelamis platurus ) is pelagic, and is seen on occasions floating in massive groups. Fish that come up to shelter under these slicks provide food for the snakes. Occasionally these yellow-bellies get washed up on beaches after storms and pose a hazard to children.

13. Aggressive only during the mating season in the winter, the sea snake is very curious, and they become fascinated by elongated objects such as high pressure hoses. Provoked snakes can become very aggressive and persistent --requiring repeated kicks from the fins to ward them off.

15. Persistent myths about sea snakes include the mistaken idea that they can't bite very effectively. The truth is that their short fangs (2.5-4.5mm) are adequate to penetrate the 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.

17. You tube videos • Intense pain is not obvious at the site of the sea snake bite; 30 minutes after the bite there is stiffness, muscle aches and spasm of the jaw followed by moderate to severe pain in the affected limb. There follows progressive CNS symptoms of blurred vision, drowsiness and finally respiratory paralysis. A specific antivenom is available.