Specimens of Callinectes danae Smith 1869 were caught in northeastern Brazil (2178 males, 2031 females); of these, 24 males and 24 females were reared for 6 months. Water temperature (T) and salinity (S) showed a significant effect on the average ecdysis in wild crab (μ), with a model obtained that was: μ = exp(−0.12268T + 0.06148S)/(1 + exp(−0.12268T + 0.06148S)). Size at morphometric maturity was significantly larger for wild males and females (9.45 and 8.38 cm, respectively) than for reared individuals (8.95 and 7.93 cm). Females of sizes above CW50 (carapace width at maturation) showed an increased ecdysis activity, whereas males showed a decrease in ecdysis frequency in sizes over CW50. Five and six molts were observed for females and males, respectively, in both wild and reared crabs; the modal classes of the reared crabs were shifted to smaller sizes. In reared females the terminal-pubertal molt occurred at 107 days of age and at 148 days, on average, in males. The intermolt period varied from 8 to 41 days and increased with age.