3种西藏土著鱼类幼鱼水温耐受性的初步研究

本试验旨在探索3种西藏土著鱼类幼鱼水温耐受性。试验鱼初始饲养水温为12℃。选用拉萨裸裂尻鱼(3月龄)、异齿裂腹鱼(2月龄)、双须叶须鱼(3月龄)各90尾,各分为3个试验组,每个试验组设3个平行,每个平行10尾鱼。其中,2个试验组为升温、降温试验,1组为对照。通过每1h上升或者下降1℃,适应3h,观察并记录每个温度下试验鱼的死亡率、摄食情况、活动情况及鳃呼吸频率等。试验结果表明,拉萨裸裂尻鱼幼鱼、异齿裂腹鱼幼鱼和双须叶须鱼幼鱼摄食水温分别为8～27℃、8～25℃和7～26℃;温度过高,3种试验鱼均表现出侧游,呼吸急促,反应急躁;温度过低,试验鱼不摄食,不活动,呼吸微弱。极限最高温度分别为32.3、32.4℃和30.2℃,极限最低温度分别为0、0.4℃和0℃。温度耐受幅分别为32.3、32℃和30.2℃。因此,这3种西藏土著鱼类温度耐受幅较广,以温度为指标,可选择较多区域进行养殖。

Tolerance of Juveniles of Three Species Native Fishes in Tibet to Water Temperature

The mortality,food intake,activity and respiratory frequency were observed in Schizopygopsis younghusbandi younghusbandi(3month old),Schizothorax oconnori(2month old)and Ptychobarbus dipogon(3month old)in a constant temperature incubator at warming and cooling water temperature by increasing or decreasing 1℃ per hour with 3hour acclimatization from 12℃(as control group)with triplication to investigate the water temperature tolerance of the three species native fishes in Tibet.The results showed that the normal feeding was observed at water temperature of 8—27℃in S.younghusbandi younghusbandi,8—25 ℃in S.oconnori and 7—26 ℃in P.dipogon.The three fish species showed lateral swimming,breath shortness and impatience of reaction at over high temperature,and stopped feeding and moving and weakened breath at very low temperature,with the upper and lower limit temperature of 32.3℃and 0℃in S.younghusbandi younghusbandi,32.4℃and 0.4℃in S.oconnori and 30.2℃and 0℃in P.dipogon.The temperature tolerance amplitude was ranged within 32.3 ℃ in S.younghusbandi younghusbandi,32℃in S.oconnori and P.dipogonin 30.2℃,indicating that the three indigenous fish species have wide temperature tolerance,and is suitable for breeding in large area.