鳖 Trionyx sinensis；soft shelled turtle
A genus of turtles in the turtle family Turtle family.
Scientific name Chinese turtle. Commonly known as turtles, dough fish, water fish.
Widely distributed in China, Vietnam, Japan. The economic value is high, the meat is delicious, and it has been regarded as a tonic food since ancient times. A into the drug is called turtle nail.
Turtle armor
It is flattened, oval in shape, with small eyes, a long neck, a head and neck that can be fully retracted into the nail, a long snout, and nostrils at the front. The upper and lower jaws are beaks. The back is dark green or yellowish brown, and the ventral surface is white and yellowish.
It is a temperate animal.
Breathe with your lungs and often float to the surface of the water to exchange gases.
Timid, inhabits a quiet environment.
When the water temperature is lower than 20 ° C, there is a habit of basking in the sun; above 35 ° C, it likes to hide in the shade. Stop eating below 15 °C and hibernate when it drops to 10 °C.
Wild turtles feed on animal food, such as frogs, shrimp, fish, etc. Do not actively chase the bait, but when sneaking underwater, when encountering the bait, it will extend its neck and open its mouth to swallow.
Juvenile turtles weighing less than 50 grams grow slowly and are difficult to raise. After weighing more than 50 grams, the breeding is smooth. At ages 3 to 4, it grows fastest. Sexually mature at 4 years.
The male turtle's tail is longer than the skirt, and the female turtle is not.
Mating from April to May, in vivo fertilization, sperm entering the fallopian tubes remain fertilized until May to August of the following year.
The fertilized egg is a multi-yellow egg, has no air chambers, and develops in the ovaries.
In mid-May of the following year, when the water temperature rises to 28 ° C, the eggs are laid, and the eggs are laid until August, laying eggs 2 to 5 times. The eggs are nearly round, 1.5 to 2 cm in diameter and weigh 3 to 5 g.
China now uses natural spawning and artificial incubation. The incubation temperature is controlled at 33~34 °C, the relative humidity is 81%~82%, the moisture content of the sand bed is 7%~8%, and the juvenile turtles can be hatched in 40~45 days.
Raise 7 to 12 juvenile turtles per square meter, 5 to 8 young turtles, and 200 to 300 adult turtles per mu (about 667 square meters), and feed more animal protein. It takes only about 15 months to grow from a juvenile turtle to 500 grams of commercial turtles. At the same time, attention should be paid to the prevention and control of diseases.
Excerpt from: The Encyclopedia of China (2nd Edition), Volume 2, Encyclopedia of China Publishing House, 2009