Wilcox Sean C, Lappin A Kristopher
Biological Sciences Department, California State Polytechnic University, Pomona, California.
J Exp Zool A Ecol Genet Physiol. 2013 Nov;319(9):495-504. doi: 10.1002/jez.1813. Epub 2013 Aug 6.
Whole-animal performance (e.g., swimming speed, bite force) functions as a fundamental link between organism and environment and, as such, performance characteristics are important in determining the outcomes of agonistic interactions, both interspecific and intraspecific. Cannibalism is an intraspecific agonistic interaction for which winners may be expected to exhibit superior performance in characteristics relevant to cannibalistic behavior. The larvae of the Green Poison Frog (Dendrobates auratus) exhibit cannibalistic behavior in which "fast-starts" (i.e., high velocity and acceleration from a resting position) are used in attempts to bite and avoid being bitten by conspecifics. We tested the hypothesis that superior fast-start swimming performance is positively associated with winning cannibalistic interactions between similarly sized individuals. Fast-starts by larvae were imaged with a high-speed camera, and pairs of size-matched individuals then underwent interaction trials to determine whether swimming performance is associated with winning a cannibalistic interaction. Linear acceleration of the snout tip, approximating the position of the mouthparts used to attack an opponent, was significantly greater in winners than losers. At the estimated center of mass, generally representing a target for an attacking opponent, linear velocity and acceleration were significantly greater in winners than losers. Understanding the role of performance in intraspecific interactions can help elucidate how they contribute to population dynamics, and thus how such interactions ultimately drive morphological and behavioral evolution.
全动物性能（如游泳速度、咬合力）是生物体与环境之间的基本联系，因此，性能特征对于决定种间和种内争斗互动的结果很重要。同类相食是一种种内争斗互动，预计获胜者在与同类相食行为相关的特征方面会表现出卓越的性能。绿毒蛙（Dendrobates auratus）的幼虫表现出同类相食行为，其中“快速启动”（即从静止位置的高速和加速度）被用于试图咬伤并避免被同种个体咬伤。我们测试了这样一个假设：卓越的快速启动游泳性能与体型相似的个体之间同类相食争斗互动的获胜呈正相关。用高速摄像机对幼虫的快速启动进行成像，然后对大小匹配的个体对进行互动试验，以确定游泳性能是否与赢得同类相食争斗互动有关。获胜者鼻尖的线性加速度（近似用于攻击对手的口器位置）显著大于失败者。在估计的质心处（通常代表攻击对手的目标），获胜者的线性速度和加速度显著大于失败者。了解性能在种内互动中的作用有助于阐明它们如何影响种群动态，进而阐明此类互动最终如何推动形态和行为进化。
