Born to kill: Predatory functional responses of the littoral amphipod Echinogammarus marinus Leach throughout its life history
Born to kill: Predatory functional responses of the littoral amphipod Echinogammarus marinus Leach throughout its life history
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DOI：
10.1016/j.jembe.2012.10.006
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发表时间：
2013-01-01
影响因子：
2
通讯作者：
O'Connor, Nessa E.
中科院分区：
文献类型：
--
作者：
Alexander, Mhairi E.;Dick, Jaimie T. A.;O'Connor, Nessa E.
对捕食者-猎物相互作用的研究，特别是对功能反应的推导，通常集中在成年动物或单一生活史阶段，随后的食物网分析通常只是简单地使用平均体型或假设所有同种动物都是相等的。在掠夺性功能反应的背景下，这种对个体发生的有限考虑可能对我们理解群落结构和功能具有重要意义。此外，大型捕食者可能在身体上受到限制，无法捕食非常小的猎物个体和/或由于其有限的能量返回而避免这种捕食。本文研究了潮间带片足类海洋棘爪类（Echinogammarus marinus）的掠食性及其在整个个体发育过程中对猎物等足类（Jaera nordmanni）的影响。首先，野外捕获的海纹鄂蚊从幼体到成体的肠道中均存在nordmanni，表明海纹鄂蚊在个体发育过程中可能是掠食性的。其次，幼鱼、亚成虫和成虫对大小匹配的猎物表现出II型功能反应。此外，在同生境和异种生境中，最大的海褐家鼠以最小的北曼家鼠为食，同样具有II型功能响应。因此，猎物不会从捕食者的任何个体发育或体型上的庇护中受益。这些结果表明，在整个个体发育过程中，海蛸具有显著的捕食能力和潜在的种群水平影响，这可能决定了当地猎物物种的排除和持久性。因此，确定捕食者在个体发育过程中的功能反应可以提高我们对其群落影响的理解和预测。(C) 2012 Elsevier B.V.版权所有
Studies of predator-prey interactions, and in particular the derivation of functional responses, have typically focussed on adults or single life-history stages, with subsequent food web analyses often simply using average body sizes or assuming that all conspecifics are equal. Such limited consideration of ontogeny in the context of predatory functional responses may have important implications for our understanding of community structure and function. Further, large predators may be physically restricted in their ability to feed on very small prey individuals and/or avoid such predation due to its limited energetic return. Here, we elucidate the predatory nature and impact of the marine intertidal amphipod, Echinogammarus marinus, throughout its ontogeny, towards a prey species, the isopod Jaera nordmanni. Firstly, we found J. nordmanni in the guts of field caught E. marinus, from juveniles through to adults of the latter, indicating that E. marinus may be predatory throughout ontogeny. Secondly, juvenile, sub-adult and adult E. marinus exhibited Type II functional responses towards size-matched J. nordmanni prey. In addition, the largest adult E. marinus fed on the smallest J. nordmanni, again with Type II functional responses, in both homo- and heterogeneous habitat. Thus, the prey do not benefit from any ontogenetic or size refuge from the predator. These findings demonstrate the significant predatory ability and potential population level impacts of E. marinus throughout its ontogeny, which may determine local prey species exclusion and persistence. Determining the functional responses of predators throughout their ontogeny may thus improve our understanding and prediction of their community impacts. (C) 2012 Elsevier B.V. All rights reserved.