不同低温条件下吉富罗非鱼的耐受性研究

Tolerance of GIFT Tilapia (Oreochromis niloticus) under Different Low Temperature Stress

应用室内人工降温,以0.5°C/2 h的降温方法研究吉富罗非鱼的低温耐受能力,分析比较不同低温条件下吉富罗非鱼的昏迷情况和死亡情况,评价其低温耐受性。结果表明：在8、9、10和11°C持续低温胁迫下,吉富罗非鱼的昏迷温度在8.9~10.5°C,半数昏迷温度为9.6°C左右;从开始出现昏迷到全部死亡的经历时间分别为14.5、18.5、24.5和28.5 h;昏迷维持时间与累计死亡率呈显著的线性相关,分别为：y=-0.0489x2＋1.4330x-9.5078（R2=0.9999）、y=-0.013 6x2＋0.5024x-3.6385（R2=0.9649）、y=0.003 8x2-0.0461x-0.1344（R2=0.9843）和y=-0.0034x2＋0.244 3x-3.2131（R2=0.9945）。吉富罗非鱼的耐受性与时间和温度密切相关,其中8°C组耐受时间最短,11°C组最长。

The study was done to assess low-temperature tolerance of GIFT tilapia.In the condition of indoor artificial cooling,with 0.5 °C/2 h cooling down to different low temperature point,the coma and death situation are compared to evaluate their low-temperature tolerance.The results showed that coma temperature ranged from 8.9 °C to 10.5 °C,the semi-lethal duration the temperature of half coma of GIFT tilapia was about 9.6 °C.The time of GIFT tilapia from the beginning coma to dead was 14.5,18.5,24.5 and 28.5 h under low temperatures of 8,9,10 and 11 °C,respectively.The significant linear regression between the coma duration and the cumulative mortality of GIFT tilapia was y=-0.048 9x2＋1.433 0x-9.507 8（R2=0.999 9）,y=-0.013 6x2＋0.502 4x-3.638 5（R2=0.964 9）,y=0.003 8x2-0.046 1x-0.134 4（R2=0.984 3）,y=-0.003 4x2＋0.244 3x3.213 1（R2=0.994 5） at 8,9,10 and 11 °C,respectively.GIFT tilapia lowtemperature tolerance was closely related with coma duration and temperature,and 8 °C group tolerated the shortest,11 °C group the longest.