Vaughn Dawn
Department of Biology, Friday Harbor Laboratories, University of Washington, Seattle 98195, USA.
Ecology. 2007 Apr;88(4):1030-9. doi: 10.1890/06-0689.
While there are numerous reports of predator-induced morphological defenses for freshwater zooplankton, freshwater larvae, and benthic marine animals, a literature search revealed no reports of predator-induced morphological defenses for marine zooplankton. Rarity of predator-induced morphological defenses in marine zooplankton would imply a difference in predation risks compared to those experienced by freshwater organisms and benthic marine adults, whereas the presence of such plasticity in defenses would imply that risks are modified by developmental responses. This study reports a predator-induced change in defenses and vulnerability of a marine planktonic larva. Specifically, when reared in the presence of zoea larvae of Cancer spp., veliger larvae of the intertidal snail Littorina scutulata developed significantly smaller shell apertures and rounder shells than did cohort veligers reared in the absence of predator cues. Pairwise predation trials demonstrated that veligers reared with caged zoeas throughout development had greater survival than predator-naive veligers during short-term exposure to zoeas. The development of predator-induced morphological defenses by some marine larvae introduces a range of testable hypotheses on developmental plasticity that reduces vulnerability of planktonic larvae and other marine zooplankton to predators.
虽然有许多关于捕食者诱导淡水浮游动物、淡水幼虫和海洋底栖动物产生形态防御的报道，但文献检索显示没有关于捕食者诱导海洋浮游动物产生形态防御的报道。海洋浮游动物中捕食者诱导形态防御的罕见性可能意味着与淡水生物和海洋底栖成年动物相比，它们面临的捕食风险有所不同，而防御中存在这种可塑性则意味着风险会因发育反应而改变。本研究报告了一种海洋浮游幼虫的捕食者诱导的防御和脆弱性变化。具体而言，当在Cancer属的溞状幼虫存在的情况下饲养时，潮间带蜗牛粒花冠小月螺的面盘幼虫发育出的壳孔明显比在没有捕食者线索的情况下饲养的同龄面盘幼虫更小，壳也更圆。成对捕食试验表明，在整个发育过程中与关在笼中的溞状幼虫一起饲养的面盘幼虫，在短期接触溞状幼虫时，比未接触过捕食者的面盘幼虫有更高的存活率。一些海洋幼虫捕食者诱导形态防御的发展提出了一系列关于发育可塑性的可测试假设，这些假设降低了浮游幼虫和其他海洋浮游动物对捕食者的脆弱性。
