Deep Sea Bloggerhead: Sea Snakes

Sea snakes are true reptiles who shed their scaly skin, breathe air, have forked tongues. They are cold blooded but found in warm sub- and tropical seas in all seas except the Atlantic and Carribean.

The Banded Sea Snake is highly venomous and common in the Pacific:

There are ~70 sea snakes identified and some have venom stronger than a cobra's. Two families of sea snake are: the Laticaudinae (amphibious-living on land and water) and the Hydrophiinae (aquatic-never leaving the water). (62 species make up the former true snake two families) Four of the sea krait species of sea snake are laterally compressed, oviparous, and lay eggs on land. (There are three species of marine mangrove snakes in another family which are venomous and are rear-fanged. One marine file snake in a fourth family is also ovoviviparous and yet not venomous.)

Banded Sea Krait:

Here is a map of the geographic range of the true sea snakes:

     All except one genus of sea snake give live birth (ovoviviparity), can often congregate in large numbers, and chains of sea snakes in Indonesia have been known to reach almost 10 meters in length.
     They shed their scaly skin often, approximately every two weeks, feed frequently as a result of their higher metabolism, and have valvular nostrils and an elongate lung to efficiently respire as they come to the surface between every 30 mins. and two hours.
     None are found in Hawaiin waters although one species is found off San Catalina Island. Well-studied eastern pacific sea snakes are the yellow-bellied and olive sea snakes. Approximately 65% of all strikes on humans have resulted in no venom discharge and the antivenom is created from the milking of terrestrial snakes. The venom is closely related across species of all sea snakes. Sea snakes produce a toxin called Rhabdomyolysis that they inject approximately 10-15 mg into their prey via hollow fangs, causing muscle pain, muscle sensitivity and muscle spasm in humans, and neural paralysis in victims at sea.

Olive Sea Snake:

Although, in humans, pain is minimal initially, after about 30 minutes the pain worsens and the victim will experience severe pain in his/her muscles, and the area around the wound. The toxicity of the sea snake venom is so intense that the average snake could kill more than five men, while the two deadliest sea snakes, Oxyuranus microlepidotus and Oxyuranus scutellatus, could kill 125 men.

The Yellow Bellied Sea Snake is a highly venomous sea snake found in all tropical oceans excpet the Atlantic: