Invasion of an Exotic Cladoceran into North American Reservoirs

摘要96-15374奥布莱恩入侵北美水库外来枝角类入侵非本土物种的入侵可能会取代或支配本土物种，从而造成严重的问题。最近的一次入侵就是大型浮游动物大型水蚤的入侵，这种浮游动物正在入侵北美东南部和中南部的水库。在过去的五年中，D.Lumholtzi入侵了21个州的124个水库，其中包括密苏里州的29个水库和堪萨斯州的5个水库。Laphnia Lumholtzi的头和尾刺非常大。这些特征有望减少捕食，并增加它们与其他缺乏类似结构的达夫类动物相比的竞争优势。因此，这种物种的入侵可能会极大地改变淡水食物网，而在淡水食物网中，达夫类动物往往是关键物种。在这个项目中，我们将调查Dumholtzi在堪萨斯州和密苏里州水库的动物地理分布，并将进行广泛的平行湖沼学测量。我们将学习(1)什么条件影响入侵的可能性，以及(2)对入侵的食物网的生态影响。

ABSTRACT 96-15374 O'Brien Invasion of an exotic Cladoceran into North American Reservoirs Invasions of non-native species can cause profound problems by displacing or dominating indigenous species. One such recent invasion is that of Daphnia lumholtzi, a crustacean zooplankter that is invading the reservoirs of southeastern and south central North America. During the last five years D. lumholtzi has invaded 124 reservoirs in 21 states, including 29 reservoirs in Missouri and 5 in Kansas. Daphnia lumholtzi has an unusually large head and tail spines. These features would be expected to reduce predation and increase their competitive advantage compared with other daphnids lacking similar structures. The invasion of this species thus may dramatically alter freshwater food webs, where daphnids are often keystone species. In this project we will investigate the zoogeographic distribution of D. lumholtzi in Kansas and Missouri reservoirs, and will carry out extensive parallel limnological measurements. We will learn (1) what conditions affect the likelihood of invasions, and (2) the ecological effects on invaded food webs.