Modeling effect of thermic amplitude on growing Chinese shrimp, Penaeus chinensis (Osbeck)

A 40-day study evaluating the effect of thermic amplitude on daily growth rate of Chinese shrimp was conducted. Three thermic regimes consisting of one constant temperature (31°C) and two daily thermocycles were selected. The temperatures of the two thermocycles increased from 29 to 33°C and from 27 to 35°C, respectively, on a 12-h cycle, and then decreased to their respective origins on the following 12-h cycle. sults indicated that the growth rate was a quadratic function of the thermic amplitude. Such a growth model may be described by G=0.02718846+0.0023323775(TA)−0.000487611(TA)2 G represents the daily growth rate on a 40-day basis, and TA is thermic amplitude in centigrade. The optimal thermic amplitude was estimated to be 2.39°C. That is, the maximum daily growth rate would be 0.0299779 at daily temperatures fluctuating between 31°C ± 1.195°C; or practically, the optimal daily temperatures would be fluctuating between 30 and 32°C.