VETERINARY MEDICINE: How sea snakes, surrounded by salt water, quench their thirst.

VETERINARY MEDICINE: How sea snakes, surrounded by salt water, quench their thirst.Water, water everywhere, and not a drop to drink. Such is the lot in life for thirsty sea snakes—and yet they’ve found a way to thrive. Most yellow-bellied sea snakes spend their entire lives at sea. They rarely end up on land and are vulnerable there, since their paddle-shaped tails and keeled undersides make crawling difficult. Armed with potent venom, they drift in a vast territory that encompasses much of the world’s oceans, riding the currents and hunting fish near the sea surface. Like other reptiles, these creatures need to drink water to survive. How does an animal surrounded by saltwater quench its thirst? It used to be thought that these serpents drank from their salty surroundings. “Previous textbook dogma was that sea snakes drank seawater and excreted the excess salts using their sublingual salt glands,” explains Harvey Lillywhite, a biologist at the University of Florida. Recent work has proven that false—and a new study suggests that yellow-bellied sea snakes (Hydrophis platurus) rehydrate at sea by drinking rainwater that collects on the ocean surface.