Department of Fisheries Biology, Humboldt State University, Arcata, California, USA.
U.S. Forest Service, Pacific Southwest Research Station, Arcata, California, USA.
J Fish Biol. 2021 May;98(5):1321-1328. doi: 10.1111/jfb.14664. Epub 2021 Jan 21.
Identification of introduced species can be important to understanding ecological systems and meeting conservation and management goals, but the process can be surprisingly challenging. The Klamath smallscale sucker Catostomus rimiculus seems likely to be native to the Smith River because the drainage separates two basins believed to be within the fish's native range, the Rogue and Klamath rivers. Further, C. rimiculus is broadly distributed in the Smith River, and the indigenous Dee-ni' People of the Smith River have a unique word for sucker. Nonetheless, a historical survey of fishes that described C. rimiculus from the Rogue and Klamath rivers did not include C. rimiculus among the fishes of the Smith River. To determine whether the genetic structure of the Smith River C. rimiculus reflects expectations for a native sucker population, the authors of this study examined variation in microsatellite and mitochondrial genetic markers from the Smith River and surrounding drainages. The genetic analyses revealed a pattern consistent with extreme founder effects in Smith River C. rimiculus, as would be expected from a single introduction of six or fewer effective individuals. The sharing of a high-frequency haplotype between the Smith River and Klamath River that is not detected in the Rogue River suggests the Klamath River as the likely source for the introduction. The findings highlight that local-scale introductions can be easily overlooked because the newly established populations can appear to be parts of contiguous natural distributions.
鉴定引入物种对于了解生态系统和实现保护及管理目标非常重要，但这个过程可能极具挑战性。克拉马斯小脂鲤（Catostomus rimiculus）似乎是史密斯河的本地物种，因为该流域将两个被认为是其原生范围的流域—— Rogue 河和克拉马斯河——分隔开来。此外，C. rimiculus 在史密斯河中广泛分布，而史密斯河的原住民 Dee-ni' 人对脂鲤有一个独特的称呼。尽管如此，对 Rogue 河和克拉马斯河鱼类的历史调查并未将 C. rimiculus 包括在史密斯河的鱼类中。为了确定史密斯河 C. rimiculus 的遗传结构是否反映了对本地脂鲤种群的预期，本研究的作者检查了来自史密斯河及其周围流域的微卫星和线粒体遗传标记的变异。遗传分析显示，史密斯河 C. rimiculus 的遗传结构模式与极端奠基者效应一致，这与单一起源的 6 个或更少有效个体的情况相符。在史密斯河和克拉马斯河之间共享一种高频单倍型，但在 Rogue 河未检测到，这表明克拉马斯河是引入的可能来源。研究结果表明，局部尺度的引入很容易被忽视，因为新建立的种群可能看起来是连续自然分布的一部分。
