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

摘要建议编号DEB-0108439詹姆斯·F·吉尔姆北卡罗来纳州立大学RUI：合作研究：危险环境中的猎物运动：热带溪流鱼的研究本研究的目的是探索捕食者和个体变异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者威胁的增加，捕食性鱼类物种的增加是否减缓了捕食者物种通过河流受威胁区域的扩散速度(先前的一项研究发现，捕食性鱼类增加而不是抑制了猎物的移动)。第二个问题评估了个体在探索家园以外范围的倾向上的大胆是否有助于种群内的分散率，如果是的话，个体差异是否遗传。田野调查将在特立尼达的天然溪流中进行，这些溪流中含有猎物物种，但它们所包含的捕食者物种的数量不同。每条溪流中的移动将通过标记-重新捕获程序来确定。大胆的个体差异将通过行为分析来评估，其遗传力将通过养育搬迁者和非搬迁者的后代来评估。为了直接确定个体大胆程度的差异是否有助于自然界中的扩散速度，将在一条河流的两条姊妹支流上进行相互移植实验，其中一条支流的迁移者将交换另一条支流的留守者。如果大胆是一种个体特征，那么这两条河流最终应该包含扩散速度不同的种群。拟议的鱼类研究结果有望为了解影响热带河流自然栖息地扩散的因素开辟新的途径。

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.