STUDIES ON THE BREEDING ECOLOGY OF THE TORTOISE, CHINEMYS REEVESII(GRAY)

The breeding season of tortoise lasts from May to August, but the peak of spawning occurs in the first ten-day of July. The temperature for breeding was found to be 20-38℃ and the optimal temperature at 31℃. The eggs were laid in nest situated 30 cm above water surface. The construction of nests for egglaying was carried out mainly by the females at night. Nests were digged vertically, being about 50 mm in depth, with a diameter of about 41ram at the opening and 50 mm around the bottom. Clutch size varied from 1 to 13 eggs, with a mean of 5.6 eggs. Eggs are ellipsoidal, white in color and opaque. The relationship between weight (W) and axis (L1 L2) of egg may be expressed as W=0.001405+0.186111 and W=0.000589+0.332912 When the number of females were three times as that of males, the average fetilization rate of eggs were estimted to be 79.73%. Accumulated temperature for hatching were 4125°C.h. The incubation lasted 64.39 days (indoor) and 76 days (outdoor) and the hatching rates were 87.6% (indoor) and 15.79--55.6% (outdoor), respectively. Tortoise just hatched were 4.15±0.1037(g) in weight.Results of hatching rate in relation to several artificial hatching conditions are also dealt with in the paper.