(1) Age of sexual maturity: Under natural conditions, the gonads of turtles over 5 years old begin to mature, and mature well at 7 years old. Judging from the weight, the average male turtle weighs 150 grams and the female turtle starts to mature sexually at 250 grams.

(2) Mating and fertilization: From April to May every year, when the moon just rises above the treetops, you can see turtles chasing each other beside the pond. Sometimes a female turtle is followed by 1 to 3 male turtles. At first, the female turtle ignored her, but as time went by, the strong and flexible male turtle jumped on the female turtle's back, grabbed both sides of the female turtle's back with his forelimbs, and mated with his hind limbs standing on the ground. If they are in water, the male and female turtles roll up and down to complete mating.

(3) Egg-laying period: Turtles in tropical areas can lay eggs all year round. In the Yangtze River Basin of my country, they usually start laying eggs at the end of April and end at the end of August. The peak period of egg-laying is from May to July. Female turtles can lay eggs (nests) 3 to 4 times a year, with an interval of 10 to 30 days between each time, and 5 to 10 eggs each time, with a minimum of 1 and a maximum of 16. The optimal water temperature and air temperature are 27°C to 31°C. If the temperature exceeds 35°C, spawning will stop.

(4). Egg-laying habits: The egg-laying process of turtles can be divided into four stages:

The first stage Choose acupuncture. Crawling everywhere to choose the roots of trees or weeds where the loose soil is conducive to preventing enemies. The moisture content of soil is about 5% to 20%.

The second stage is digging holes. The diameter of the egg hole is about 3 to 4 centimeters, the hole body is slightly tilted, and the depth is about 8 to 9 centimeters.

The third stage of egg laying. The eggs are laid in the hole, and after each egg is laid, it is arranged in the hole with the hind limbs. One egg is laid every 2 to 5 minutes, and it takes about 30 minutes to lay a batch of eggs.

The fourth stage is to cover the acupoints. Use both hind limbs to work in turn, scraping the soil outside the hole into the hole little by little, and press it with the hind limbs every time you put soil in. When the egg hole is covered with soil, use the entire back half of the body to compact it firmly. The entire reproductive process takes about 8 hours, and the time ratio of digging holes, laying eggs, and covering holes is about 6:1:3.

(5) Embryo development: It takes about 30 hours after the egg is laid. There will be a white spot above the shell, which is the fertilized egg. 30 days after birth, the fertilized eggs turn light purple-red, and 70 days later, the egg shell turns black. The entire incubation process takes 80 to 90 days before the hatchlings emerge from their shells.