Tortoise shell is divided into upper and lower halves. The upper part is the carapace covering the back of the body.

Tortoise shell is divided into upper and lower halves. The upper part is the carapace covering the back of the body, as shown below:

Tortoise shell is divided into upper and lower halves. The upper part is the carapace covering the back of the body, and the lower part is the abdominal armor supporting the whole abdomen. The carapace is connected to both sides of the carapace. The carapace is rectangular and arched, with a length of 7.5-22 cm and a width of 6- 18 cm.

The outer surface is brown or dark brown, with 3 ridges, 1 cervical shield, 5 spinal shields, 1 spinal shield is longer than the width or almost equal, the 2nd to 4th spinal shields are wider than the length, and the rib shields are symmetrical on both sides, with 4 on each side, 1 1, and 2 on each hip shield. The upper abdomen is plate-shaped and nearly rectangular, with a length of 6.4 ~ 2 1 cm and a width of 5.5 ~ 17 cm. The outer surface is yellowish brown to brownish black with 12 shield.

Living habits of sea turtles

1, amphibious

Turtles breathe with their lungs and have horny nails on their bodies, which can reduce water evaporation. Sexually mature turtles lay eggs on land without going through the complete aquatic stage.

2. The universality of food

Turtles are omnivores. In nature, animal feed mainly includes worms, small fish, shrimp, snails, clams, earthworms, animal carcasses and viscera, hot pig blood and so on. And the plant feed mainly includes plant stems and leaves, melon skin, wheat bran and so on.

3. Obvious stage

The first is the feeding stage. Feeding began at the end of April (water temperature 15 degrees started, 18 degrees above normal), accounting for about 2-3% of the turtle's weight. From June to August, the food intake was vigorous, accounting for about 5-6%, and it decreased in 10, accounting for about 1-2%. The second is the dormant stage. The tortoise is a temperature-changing animal, and its body temperature changes with the outside temperature.

4. Structure and characteristics of crustaceans

The carapace consists of a large backboard and surrounding side plates. The back plate is round or oval and can be completely closed with the turtle's body. There are many hard shields on the backboard. These shields are the surface of the carapace, which is composed of cutin and plays a role in protecting the bone structure. There are rings on the shield, and the turtle's age can be judged by observing the rings.