The growth patterns of juvenile and precocious Chinese mitten crabs, Eriocheir sinensis (Decapoda, Grapsidae), stocked in freshwater lakes of China

Stocking experiments with Eriocheir sinensis were conducted in two small, s hallow lakes to study its growth pattern in 1994-1997. For the initially im mature crabs, carapace width (CW) increases from 21.2 +/- 0.4 mm (mean +/- s.e.) for females and 22.3 +/- 0.5 mm for males in January, to 65.4 +/- 0.5 mm for females and 66.9 +/- 0.6 mm for males in October. There is no signi ficant difference in CW and carapace length (CL), although there is a large difference in body weight (BW) between sexes in every month from January t o August when crabs are juvenile, however, there are significant difference s in CW, CL. and BW between sexes after September when the crabs become sex ually mature. The growth curve from January to October fits a logistic equa tion and may be expressed as CW = 75.7 (1 + exp (0.914 - 0.011t))(-1) for f emales, and CW = 77.5 (1 + exp (0.889 - 0.011t))-1 for males, where CW is i n mm, t in days. For precocious crabs (reaching maturity by the first autum n, CW does not change much from January to July, which indicates that preco cious crabs stop growing. Like juveniles, the precocious crabs show no diff erences in CW and CL, but do show a statistically significant difference in BW between sexes.