Lampert Winfried
Fachbereich Biologie (Zoologie) der J.W. Goethe-Universität, Siesmayerstr. 70, D-6000, Frankfurt/M., Federal Republic of Germany.
Oecologia. 1978 Jan;36(3):363-369. doi: 10.1007/BF00348062.
The dependency of the fecundity of Daphnia spec. on the food concentration was studied in Lake Constance. To eliminate the influence of temperature the number of eggs per adult female was plotted against the concentration of particulate carbon (<50 μm) at the estimated time of the production of the eggs. The curve obtained is similar to the results of laboratory investigations. The minimum food concentration for egg production is slightly above 0.2 mg C/1; at 0.7 mg C/1 the curve reaches a plateau. The absolute values of the threshold concentration and the "incipient limiting level" are compared to laboratory results. It appears that the shift of the field curve to higher concentrations is caused by the imcomplete availability of the 50 μm particulate carbon fraction to the daphnids. Daphnia in Lake Constance seem to be food limited during most of the year.
在康斯坦茨湖研究了水蚤属的繁殖力对食物浓度的依赖性。为消除温度的影响，将每个成年雌体的卵数与产卵估计时间的颗粒碳（<50μm）浓度作图。所得曲线与实验室研究结果相似。产卵的最低食物浓度略高于0.2mg C/1；在0.7mg C/1时曲线达到平稳期。将阈值浓度和“初始限制水平”的绝对值与实验室结果进行了比较。看来野外曲线向较高浓度的偏移是由于50μm颗粒碳部分对水蚤的可利用性不完全所致。康斯坦茨湖的水蚤在一年中的大部分时间似乎都受到食物限制。
