Section of Ecology and Systematics, Cornell University, Ithaca, NY 14853.
Proc Natl Acad Sci U S A. 1986 Jul;83(13):4831-3. doi: 10.1073/pnas.83.13.4831.
The copepod Diaptomus sanguineus begins diapause in permanent ponds in late March as an adaptation to avoid summer fish predation. During a study of copepod populations in two Rhode Island ponds, a severe drought dried one pond killing all fish. The second (control) pond did not dry, and no fish were killed. Before the drought copepods in the two ponds entered diapause on nearly the same date. After the drought, the timing of diapause shifted to later in the year in the pond that had lost its fish, while no shift occurred in the control pond. The direction of this shift in the onset of diapause is that expected had the copepods been released from natural selection for early spring diapause imposed by summer fish predation.
桡足类动物 Diaptomus sanguineus 作为一种适应策略,会在三月底进入永久池塘的滞育期,以避免夏季鱼类捕食。在对罗德岛两个池塘中的桡足类种群进行研究时,一场严重的干旱使一个池塘干涸,导致所有鱼类死亡。第二个(对照)池塘没有干涸,也没有鱼类死亡。在干旱之前,两个池塘中的桡足类几乎在同一日期进入滞育期。干旱后,失去鱼类的池塘中桡足类滞育的开始时间推迟到了一年中的较晚时间,而对照池塘中则没有发生这种变化。这种滞育开始时间的变化方向与桡足类动物因夏季鱼类捕食而被释放出对早春滞育的自然选择预期的方向一致。