Complex Predator-Prey Interactions in Marine Soft-Bottom Communities: Crabs, Clams, and Patch Dynamics

本研究的总体目标是确定 定量地，相互作用的调节因素和潜在的 海洋软底中捕食者-被捕食者动力学机制 社区研究人员有广泛的背景知识， 以及创新的超声波生物遥测技术， 研究捕食者-猎物复合体在一个小的子河口（ 位于切萨皮克湾的罗德河。 研究人员将测量 捕食者行为的组成部分，导致变化， 功能性和聚集性反应。捕食者-猎物复合体 包括大型蓝蟹（Callinectes sapidus）， 常见的底栖蛤类（Macoma balthica和Mya arenaria）以及吃小蓝蟹。 底栖 鱼类也是大量的食肉动物， 虹吸管和其他底栖无脊椎动物， 沉积物，但不是整个大蛤蜊。 早期的工作集中在 猎物种类、沉积物类型和猎物的相互作用 密度对猎物遭遇强度的持久性 捕食，重点是蓝蟹的功能反应 以蛤蚌为食 生物遥测技术已被用于确定 捕食者行为的变化尺度和关键之间的运动 猎物区 因此，这些研究集中在蓝蟹 与猎物补丁的聚集反应，这将 调节因素、潜在机制和产生的动态 这个捕食者-被捕食者系统。本研究将：（1）确定 交互因素（猎物种类、猎物密度和捕食者） 密度）调节主要捕食者的聚集反应 （大青蟹）; 2）确定交互因素（密度 猎物的分布，栖息地避难所和捕食者密度） 调节捕食率对两个交替猎物（蛤和 小螃蟹）;和3）调查行为/生理 大型蓝蟹聚集在猎物补丁的机制， 在小螃蟹和蛤蜊之间切换

The overall goal of this research is to determine quantitatively, the interactive regulatory factors and underlying mechanisms of predator-prey dynamics in a marine soft-bottom community. The researchers have extensive background knowledge as well as an innovative ultrasonic biotelemetry techniques to examine the predator-prey complex in a small sub-estuary (the Rhode River) of Chesapeake Bay. The researchers will measure the components of predator behavior which lead to changes in the functional and aggregative responses. The predator-prey complex includes large blue crabs (Callinectes sapidus) which feed on two common species of infaunal clams (Macoma balthica and Mya arenaria) as well as cannibalizing small blue crabs. Demersal fish are also abundant predators which feed extensively on clam siphons and other benthic invertebrates which live in the sediments, but not on large whole clams. Earlier work focused on the interactive effects of prey species, sediment type, and prey density on the persistence of prey encountering intense predation, with emphasis on the functional response of blue crabs foraging on clams. Biotelemetry has been used to determine the scales of variation in predator behavior and movement between key prey patches. Thus, these investigatins focus on the blue crab's aggregative response with prey patches, which links the regulatory factors, underlying mechanisms, and resulting dynamics of this predator-prey system. This research will: 1) determine the interactive factors (prey species, prey density, and predator density) regulating the aggregative response of the main predator (large blue crabs); 2) determine the interactive factors (density and distribution of prey, habitat refugia, and predator density) regulating predation rates upon two alternate prey (clams and small crabs); and 3) investigate the behavioral/physiological mechanisms of large blue crabs aggregating in prey patches and switching between small crabs and clams.