The tortoise has no teeth, but chews food with a keratinized mouth. Turtles mainly eat plant foods such as seaweed, and sometimes eat animal foods such as fish and shrimp.

Due to the long-term adaptation to life in the sea, there are salt-discharging glands at the back of the eye socket, which can discharge excess salt from the body through the eye margin. April ~ 10 is the breeding season of turtles every year. In estrus, their activities are very frequent. They actively look for their "partners", and then they both chase after each other and live a sweet "love life". At night, the female turtle quietly climbed to the shore to find a suitable spawning ground. Female turtles lay more than 100 every year, but they have to lay eggs several times. After laying eggs, it carefully covers the eggs with sand, fills the egg pits, hides them without leaving any trace, and hatches by sunlight. About two months later, the little turtle hatched. There are not many species of sea turtles, only 7 species have been found so far, and there are 4 species in China. They mainly live in Nansha and Xisha Islands in China. The life span of turtles is quite long, and some of them can live to 100 years old.

Turtle, a kind of turtle; The green turtle is the largest turtle in the turtle family. The thick crustacean is more than one meter long and weighs 150- 180 Jin. It swims in the sea all the year round, and only in the annual breeding season does the female turtle climb to the shore to lay eggs.