温度对南方鲶幼鱼生长与发育的影响

Effect of Temperature on the Growth and Development of Larva Sothern Catfish(Silurus Meridionalis Chen)

对人工刚孵化出膜的卵黄囊期仔鱼至 3周龄南方鲶幼鱼进行 15°C ,18°C ,2 1°C ,2 4°C ,2 8°C ,32°C及常温 (16 8°C～ 2 3 6°C)条件下的养殖试验 .定时观察其发育状况 ,测定体长、体质量 .发现温度极显著影响南方鲶幼鱼的发育 .统计分析表明 :温度对南方鲇的生长具有明显的影响 ,生长率随着温度的上升而增加 ,在 2 8°C达到最大值 ,而在 32°C反而下降 ,2 8°C与其他温度梯度的生长率相比具有极显著的差异 .回归分析证明各温度梯度的体长 (l)、体质量 (m)均符合关系式m =alb(a ,b为常数 ) .生长率 (r)与温度 (t)相关关系式为 :r=- 1 4188+ 0 0 997t- 4 0× 10 -5- 5t3通过求导推算极值的方法 ,求得该种鱼的最适生长温度为 2 8 82°C ,此时的最大生长率推算值为0

Larvae of southern catfish( Silurus meridionalis Chen)were got by artificial propagation. They were raised at controlled temperature of 32°C,28°C,24°C,21°C,18°C,15°C and room temperature , respectively, in the laboratory. The stages were observed in every week. And body length and body weight was measured every week for 3 successive weeks after hatching to investigate the growth rate of the larvae at these temperatures. Significant difference was found in development among these groups. Statistic analysis reveals significant difference in growth existing among different temperature groups. The highest growth rate was found in the group raised at 28°C. These results indicate that the growth rate is closely related to temperature. The correlation between the growth rate and temperature can be expressed as follow:r=-1 4188+0 0997t-4 0×10 -5 -5t\+3From this equation, the optimal temperature, at which the larvae may have the highest growth rate of 0 497 g/week, was estimated to be 28 82°C. In addition, the relationship between body length and body weight in all groups can be expressed as m=al\+b.