Even though sea snakes are surrounded by gallons of water they wait for fresh rain water to quench their thirst, a new study finds.
The discovery was made by University of Florida biologists. They found that sea snakes can go months on ends dehydrated, until they receive fresh water from rainfall.
"These snakes refuse to drink salt water, even when dehydrated," Professor Harvey Lillywhite, lead author of the study, said in a press statement. "They need fresh water to survive."
The three-year study was conducted on the Yellow-bellied Sea Snake. This species is the most widely distributed pelagic sea snake, which inhabits tropical oceans. Experiments conducted in the lab and field revealed that this marine reptile shunned salt water, taking a drink only when fresh water was available.
What's interesting is that sea snakes can sense fresh water and distinguish it from sea water. The snake spends most of its time in deep waters but during or after a rainfall, it surfaces to take a sip of fresh water. The consumption varies from just a few sips to up to 25 percent of its body mass. This amount largely depends on the availability of fresh water and how dehydrated the snake is.
The study was conducted in Costa Rica where the open ocean is like a desert, especially during the dry season, which lasts for up to six months. During this time, the sea snake loses up to 25 percent of its body mass, a level that is considered way past lethal for a human.
"Understanding the water requirements and drinking behaviors of marine vertebrates could help with conservation efforts," Lillywhite said, according to Fox News. "In areas of intensifying drought, they will need to move or die out."
The study contradicts popular beliefs that marine vertebrates have evolved to use salt water to meet their water requirements. According to previous studies, such creatures drink sea water, distilling the water by excreting excess salt via salt glands.
The new findings of the study have also raised some serious concerns about the fate of this snake species. Diminishing rainfall might be the cause of declining populations of sea snakes in some areas. If global climate change causes drought conditions to worsen, sea snakes and other marine vertebrates that depend on rainfall for fresh water could be endangered.
Currently, there are more than 60 species of entirely marine sea snakes and eight species of sea kraits that live in the sea but spend some time on shore.
The study was published in the Proceedings of the Royal Society B.
