Tortoise shell has two layers, the outer layer is keratin shield, which is a derivative of skin epidermis and attached to the bone plate, and the inner layer is the bone plate.
The lines on the tortoise shell shield are called growth lines, also called concentric lines. A growth line represents a growth cycle. When growing, the bone plate will extend and the keratin shield will not form. This is the open line.
Optimum temperature of snapping turtle;
Normal life at 38 degrees and 2 degrees, normal wintering above 1 degrees, shallow hibernation below 12 degrees, deep hibernation at 6 degrees, normal feeding at 17 degrees 17 degrees, optimal activity at 20 degrees and 33 degrees, optimal growth at 28 degrees and 30 degrees,
The basic habits of big snapping turtles and small snapping turtles are similar. Usually it is not easy to fight in water, but it can be rushed and bitten on land. Fingers and toes are webbed, aquatic, inhabiting deep rivers, lakes and swamps, and occasionally touching salt water.
Crocodile turtles have good adaptability to shallow water and deep water under artificial breeding conditions, but they should be given shallow water environment because of their poor swimming ability in larval stage.