Sea snakes generally consume different kinds of fish, such as eel, according to the Encyclopedia Britannica. Sea snakes also need to drink fresh water.
Some sea snakes eat more than just fish, including crustaceans, and a few live exclusively on fish eggs. The yellow-bellied sea snake drinks water from the top of the ocean when it rains. This species can go as long as half a year before needing another drink of fresh water.
The term sea snake covers a wide range of snakes, although they are all in the cobra family. Unlike many reptiles, sea snakes give birth to live young in the sea, according to Animal Corner; the female carries the eggs inside her body until they hatch. The snakes surface to breathe air, but they can wait as long as a third of a day before doing so; they can use their skin to breathe, and they have a single large lung.