Alfred Schroeder Lauren, Callaghan William M
Department of Biology, Youngstown State University, USA.
Ohio State University College of Medicine, 370 West Ninth Ave., 43210, Columbus, Ohio, USA.
Oecologia. 1982 Jan;53(2):238-244. doi: 10.1007/BF00545670.
Dry matter, nitrogen, and energy budgets were determined for laboratory cultures of Hydra pseudoligactis reared at 10, 15, 20, and 25° C, and fed freshly collected zooplankton. Maximum specific feeding rates increased from 0.24 to 0.91 (KJ food/KJ Hydra) with increasing rearing temperature. The corresponding growth rates increased from 0.14 to 0.29 but gross (growth/ingestion), net (growth/(ingestion-egestion)), and assimilation (gross/net) efficiencies decreased with increasing temperatures. The requisite food densities to maintain maximum ingestion rates (when permitted to feed for 3 hrs day) increased from 0.0056 to 0.021 KJ of zooplankton/KJ of Hydra. The combination of increasing energy requirements, decreasing food supply, and efficiencies of food utilization, with increasing water temperatures may contribute to the rapid declines of Hydra populations that are often observed in temperate lakes.
测定了在10、15、20和25摄氏度下饲养的拟寡水螅实验室培养物的干物质、氮和能量预算，并投喂新鲜采集的浮游动物。随着饲养温度的升高，最大特定摄食率从0.24增加到0.91（千焦食物/千焦水螅）。相应的生长率从0.14增加到0.29，但总（生长/摄食）、净（生长/（摄食-排粪））和同化（总/净）效率随温度升高而降低。维持最大摄食率（当允许每天摄食3小时）所需的食物密度从0.0056增加到0.021千焦浮游动物/千焦水螅。随着水温升高，能量需求增加、食物供应减少以及食物利用效率下降，这些因素共同作用可能导致在温带湖泊中经常观察到的水螅种群数量迅速下降。
