Dissertation Research: Morphology and Swimming Ability of Trout: Do Body Shape and Swimming Stamina Differences Mediate the Invasion of Native Cutthroat Trout Populations?

外来鱼类是造成全球许多鱼类种群数量减少和灭绝的原因。 在北美西部，外来虹鳟鱼（Oncorhynchus mykiss）的引入经常导致本地割喉鳟鱼（O。clarki）种群。这些物种在溪流中有相似的生态，因此它们被认为会争夺有限的资源。 在近亲鱼类中很常见，割喉鱼和虹鳟鱼能够杂交产生可繁殖的杂交后代。 杂交鳟鱼的竞争能力可能对剩余的本地割喉种群的入侵有很大的影响。 初步结果表明，虹鳟鱼和第一代杂交与黄石切割喉鳟（O。C. bouvieri）是更好的竞争对手的喂养领土比本地黄石割喉鳟鱼。 除了行为上的差异外，体型对鲑科鱼类的竞争互动和游泳能力也很重要。这项建议的目的是调查黄石公园的切喉鳟鱼，虹鳟鱼，和他们的杂交种之间的形态和游泳能力的差异。 亲本和杂交鳟鱼将在一个共同的环境中，以确定形态的遗传基础，并确定是否有更高的持续游泳能力，可以提供竞争优势的非本地和杂交鳟鱼。 这项研究的更广泛的影响将是提供一个更好的了解机制，引进鳟鱼取代本地鳟鱼。 该项目将支持博士生的论文研究。

Nonnative fishes are responsible for declines and extinction of many fish populations worldwide. In western North America, the introduction of nonnative rainbow trout (Oncorhynchus mykiss) frequently leads to the decline and extinction of native cutthroat trout (O. clarki) populations. These species share a similar ecology in streams, thus they are thought to compete for limited resources. As is common in closely related fish species, cutthroat and rainbow trout are able to interbreed producing fertile hybrid offspring. The competitive abilities of hybrid trout may have strong effects on the invasion of remaining native cutthroat populations. Preliminary results indicate that rainbow trout and first generation hybrids with Yellowstone cutthroat trout (O. c. bouvieri) are better competitors for feeding territories than native Yellowstone cutthroat trout. In addition to behavioral differences, body shape is important to competitive interactions and swimming ability in salmonid fishes. The goal of this proposal is to investigate differences in morphology and swimming abilities between Yellowstone cutthroat trout, rainbow trout, and their hybrids. Parental and hybrid trout will be raised in a common environment to determine the genetic basis of morphology and to determine if nonnative and hybrid trout have a higher sustained swimming ability which could provide a competitive advantage. The broader impact of this research will be to provide a better understanding of the mechanisms by which introduced trout are replacing native trout. This project will support the dissertation research of a doctoral candidate.