Alexander J E, Covich A P
Department of Zoology, University of Oklahoma, 73019, Norman, OK, USA.
Oecologia. 1991 Sep;87(3):435-442. doi: 10.1007/BF00634603.
We examined predator avoidance behavior of the freshwater snailPhysella (=Physa) virgata in response to the crayfishProcambarus simulans. In both laboratory and field enclosure experiments snails crawled above the waterline for 2 h or longer, then returned to the water.Physella virgata react to chemical signals given off by crayfish actively foraging on conspecific snails; they do not react to inactive crayfish. Low dissolved oxygen, crowding, and disturbance of the sediments did not elicit "crawlout" behavior. Crawling above the waterline, by reducing the probability of encounter between vulnerable, thin-shelled snails and crayfish, is an adaptive response to predation.
我们研究了淡水螺类维吉尼亚膀胱螺（Physella (=Physa) virgata）针对小龙虾拟螯虾（Procambarus simulans）的捕食躲避行为。在实验室和野外围隔实验中，螺类都会爬到水线以上长达2小时或更久，然后再回到水中。维吉尼亚膀胱螺会对正在积极捕食同种螺类的小龙虾释放的化学信号做出反应；它们对不活动的小龙虾没有反应。低溶解氧、拥挤以及沉积物的扰动都不会引发“爬出”行为。爬到水线以上，通过降低脆弱的薄壳螺类与小龙虾之间相遇的概率，是对捕食的一种适应性反应。
