Collaborative Research: Prey Movement in Hazardous Environments: Studies in a Tropical Stream Fish System

摘要提案编号 DEB-0108439James F. Gilliam 北卡罗来纳州立大学 RUI：合作研究：危险环境中的猎物运动：热带溪流鱼类群落的研究本研究的目的是探讨捕食者和个体变异这两种现象对热带溪流鱼扩散的影响。它们对扩散的影响尚不清楚。 第一个问题涉及捕食性鱼类的增加是否会增加捕食性鱼类的威胁，从而减缓猎物物种在河流受威胁区域的扩散速度（之前的一项研究发现，捕食性鱼类增加而不是抑制了猎物的移动）。 第二个问题评估个体在家庭范围之外探索的大胆倾向是否有助于种群内的扩散率，如果是的话，个体差异是否会遗传。 实地考察将在特立尼达的天然溪流中进行，这些溪流含有猎物物种，但其中含有的捕食者物种数量有所不同。 每个流中的移动将由标记重新捕获过程确定。 胆量的个体差异将通过行为分析进行评估，其遗传力则通过抚养运动者和非运动者的后代来评估。为了直接确定个体胆量差异是否会影响自然界中的扩散率，将在一条河流的两条姐妹支流中进行相互移植实验，其中一条支流中的移动者将与另一条支流中的停留者交换。如果大胆是一种个体特征，那么这两条河流最终应该包含分散速度不同的种群。拟议的鱼类研究结果预计将为了解影响热带河流自然栖息地扩散的因素开辟新途径。

AbstractProposal Number DEB-0108439James F. GilliamNorth Carolina State UniversityRUI: COLLABORATIVE RESEARCH: PREY MOVEMENT IN HAZARDOUS ENVIRONMENTS: STUDIES IN A TROPICAL STREAM FISH COMMUNITYThe goal of this study is to explore the effects of two phenomena, predators and individual variation, on the dispersal of a tropical stream fish. Their effects on dispersal are unknown. The first question addresses whether increasing predator threat, with the addition of predatory fish species, slows dispersal rate of the prey species through threatened zones of a river (a previous study found that a predatory fish increased rather than suppressed prey movement). The second question evaluates if individual boldness in the tendency to explore beyond the home range contributes to dispersal rate within a population and if so, whether individual differences are inherited. Fieldwork will be done in natural streams in Trinidad that contain the prey species, but which differ in the number of predator species that they contain. Movement in each stream will be determined by mark-recapture procedures. Individual variation in boldness will be evaluated through behavioral assays, and its heritability assessed by rearing offspring of movers and non-movers. To directly determine whether individual variation in boldness contributes to dispersal rate in nature, a reciprocal transplant experiment will be done in two sister tributaries of a river in which movers in one tributary will be exchanged for stayers in the other. If boldness is an individual characteristic, the two streams should eventually contain populations that differ in rates of dispersal. The results of the proposed studies with fish are expected to open new avenues to understanding the factors that affect the dispersal in natural habitats of tropical rivers.