Even though sea snakes spend their entire lives swimming in salt water, they need to drink the good stuff, fresh.
A new study from the University of Florida has shown that even when the sea snakes are dehydrated, they will only drink fresh water (water with less that 20% salt content.)
While the study only used a few species of snakes, it was well done. It is possible that more ocean-going reptiles may take advantage of fresh water as well.
This completely changes the way scientists think the 60 or so species of sea snakes deal with their watery world. Sea snakes were once thought to filter out the salt from the water by using special internal glands.
Why is this an important finding? Many species of sea snakes may be disappearing due to rising temperatures and lack of rainfall. Either the snakes must crawl onto land and drink fresh water there or they must drink fresh rainfall falling on the ocean.
Wait, these guys drink rainfall in the middle of the ocean? It just so happens that when rain falls on the surface of the ocean, it sits there for a period of time without mixing. Fresh water is slightly lighter than salty water, this is known as the Ghyben-Herzberg lens. Sea snakes may then drink from the pool of fresh water formed on top of the ocean.
Some species of sea snakes may become extinct due to droughts!
Sea snakes are amazing serpents related to cobras and coral snakes, the elapids. While they have potent venom, sea snakes are reluctant to bite. Like all snakes, the venom is used to catch their food, not for defense as many people think. How easy would it be for you to catch a slippery swimming eel with your mouth and try and swallow the wriggling thing in the vast ocean?
Sea snake venom is potent so that the prey may become paralyzed quickly for the snake to catch and swallow. Fisherman the world over have often taken sea snakes out of nets with their bare hands without being bitten. The snakes are probably just happy to be back in the water. I of course, would have second thoughts before scaring the living daylights out of an animal with powers like that of an elapid.
I sure hope the rains return to the homes of the many species of facinating sea snakes.