Water temperature adaptability of Pseudobagrus ussuriensis

ObjectiveThe adaptability of Pseudobagrus ussuriensis to water temperature was clarified to provide re-ferences for its introduction and aquaculture in southern subtropical regions of China.MethodThe paper explored and analyzed the extreme temperature difference adaptability of P.ussuriensis,and studied the feeding intensity,breeding and blood parameters under different water temperature conditions.ResultThe tolerance range limit of P.ussuriensis mutated from high temperature changing to the low temperature was 8.0℃,and the tolerance limit range from low temperature to high temperature was 7.0℃.Its daily feeding rate were in parabolic relation with temperature,the corresponding equa-tion of linear regression was y=-0.0132 x2+0.6953x-5.0973(R2=0.7661).In the range of 11.8℃to 30.3℃,P.ussuriensis growth constant(GC)was between 0.1464 and 0.7620.It was basically not affected by high temperature.At the water tem-perature of 25.8℃,its oxytoic rate,fertilization rate,incubation rate and survival rate 30 d after hatching were the high-est,which were 73.4%,84.1%,82.6% and 75.7%. Therefore,the optimum water temperature for hatching was about 25.0℃. P.ussuriensis could maintain the integrity of its body tissues and organs and normal physiological function within 30.0℃.ConclusionThe result shows that,P.ussuriensis has excellent adaptability to water temperature environment, especially for ±7.0℃water temperature difference.It can be introduced into the southern subtropical region of China to promote aquaculture.But if the intensity of temperature difference stress is too strong or the time is too long during the transportation and overwinter cultivation,its physiological adaptation mechanism may fail.Therefore,attention should be paid to the introduction of P.ussuriensis.