What are the key measures to improve the hatching rate of turtle eggs?

1. Selection of parent turtles

Parent turtles should be selected from individuals aged over 5 years, robust, free of disease and injury, active in movement, and with strong limbs.

2. Male-to-female ratio

Generally, a female-to-male ratio of 2-3:1 is appropriate. If the proportion of male turtles is too low, it will be detrimental to normal fertilization of the females.

3. Egg collection time

Generally, collecting eggs within 10-30 hours after laying is appropriate; if conditions permit, collecting eggs within 3-5 days after laying is even better. Generally, eggs should be collected in the afternoon to avoid human interference with daytime egg-laying. Normally fertilized turtle eggs have a white spot on the outer surface of the eggshell with clear, smooth edges, and the egg is bright in color, appearing pale pinkish-white. Eggs with no white spot visible on the shell and a basically uniform color are unfertilized eggs, while those with irregular white patches on the shell are poorly developed eggs; neither can be placed in the incubation box.

4. Rearing site

For larger turtle species such as the snapping turtle, each large turtle should occupy at least 2-3 sq m of pond area to facilitate chasing, swimming, playing and mating during the breeding season. For smaller turtle species such as the Chinese pond turtle, 2-3 turtles can be stocked per sq m of pond area, aiming for a fertilized egg rate of over 96%.

5. Incubation method

Wooden boxes or river sand can be used for incubation. For the incubation box, Chinese fir is the best wood, pine is second best, and poplar or willow should not be used. River sand has good aeration and water retention. Turtle eggs can be arranged on a 3 cm thick layer of sand, then covered with 2-3 cm of sand. Note that sea sand must not be used, because sea sand contains too much salt, which will cause the embryos to die from salt damage.

Turtle eggs prepared for incubation must all be disinfected before incubation. The sand used can be disinfected by sprinkling with a 5000-fold potassium permanganate solution, then sun-dried and placed into the incubation box to kill harmful pathogens. The humidity of the incubation box can be controlled at 80%-86%. The incubation temperature is best at 30-33°C.