温度对水螅种群增长和个体大小的影响

Effects of temperature on population growth and body size of Hydra sp.

应用群体累积培养法,以枝角类为食物,在10℃、20℃和30℃三种温度下,研究了温度对水螅(Hydrasp.)种群密度、种群增长率和个体大小的影响。结果表明温度对水螅种群密度和个体体积由极显著影响。在培养初期,30℃下的水螅种群密度最大;而在培养后期,20℃下的水螅种群密度则显著大于30℃下的值;10℃下的值则始终最小。在同一温度下,种群增长率均与时间呈曲线相关,10℃、20℃、30℃的回归方程分别为:Y=0.000433X2-0.00262X+0.00332、Y=-0.003367X2+0.068335X-0.066489、Y=-0.018469X2+0.188952X-0.030933。在研究范围内,30℃的水螅个体最小。

By means of population accumulative culture and feeding with cladoceans,the effects of temperature on the population growth and body size of Hydra sp.were studied at 10℃,20℃ and 30℃.The results showed that the population density and body size were both significantly affected by temperature.Population density at 30℃ was the largest during the original several days,but the population density at 20℃ was significantly larger than that at 30℃ during the last several days.Population density at 10℃ was smallest among all of the periods.At the same temperature,the relationship between the time and the population growth rate were curvilinear,with the following regression equation:Y=0.000433X^2-0.00262X+0.00332(10℃),Y=-0.003367X^2+0.068335X-0.066489(20℃),and Y=-0.018469X^2+0.188952X-0.030933(30℃).Hydra got the minimum body size at 30℃.