Compensatory Growth of Juvenile Brown Flounder Paralichthys olivaceus Following Low Temperature Treatment for Different Periods Compensatory Growth of Juvenile Brown Flounder Paralichthys olivaceus Following Low Temperature Treatment for Different Periods

We investigated the effects of low temperature(8.5℃) on the growth and feeding rates and feed conversion efficiency of juvenile P.olivaceus with an average initial weight of 3.87 ± 0.06 g(mean ± SE).Fish were exposed to 8.5℃ for 0(control),1,2,3 and 4 weeks,and then to 20℃ for 10,9,8,7 and 6 weeks,respectively.Low temperature clearly led to growth depression.The weight of fish exposed to low temperature for 1 week was restored to that of control,while that of fish exposed to low temperature longer was significantly decreased(P < 0.05).During the entire low-temperature period,specific growth rate,feeding rate and feed conversion efficiency of the fish were significantly lower(P < 0.05) than those of control,while in the whole recovery period,specific growth and average feeding rate were markedly higher(P < 0.05) than those of control.At the end of experiment,only the feeding rate of the fish exposed to low temperature for 1 week was not significantly different from that of control(P > 0.05).Feeding rate and feed conversion efficiency were reduced at low temperature in juvenile P.olivaceus.The compensatory growth of juvenile P.olivaceus may therefore be attributed to the improvement of feeding rate.Our results suggested that growth depression occurs when juvenile P.olivaceus are exposed to low temperature for more than one week