Effects of temperature on the respiration of GIFT strain of Nile tilapia (Oreochromis niloticus)

Abstract:

Experiments were conducted and the respiratory rate of the GIFT strain of Nile tilapia(Oreochromis niloticus), DO,pH,carbon dioxide and ammonia in water were analyzed to evaluate the effects of temperature from 10-30 ℃ on the respiration of experimental fish.The results indicated that the oxygen consumption rate (Y_cr) and the ammonia excretion rate (R_an) of GIFT increased with water temperature (t), and the regression equations were Y_cr = 0.003 8 t²-0.002 3 t + 0.031 2(R² = 0.954 9) and R_an = 0.000 9 t²-0.002 7 t + 0.003 7(R² = 0.947 5) respectively;The ammonia quotient(Q_a) was 0.016-0.099(< 0.33), and the proportion of protein as energy supply was 5 %-30 %, which indicated that the energy consumption of GIFT was mainly offered by fat and carbohydrate.The carbon dioxide excretion rate declined from 0.068 4 to 0.011 4 mg /(g·h) with the temperature decreasing from 30 ℃ to 15 ℃. pH in effluent was lower significantly than that in influent while the reduction increased with the rising of the temperature.The respiratory quotient(Q_r) of GIFT was 0.55 ± 0.10 (< 1), which indicated that aerobic respiration was the main respiration style of GIFT.