Canales-Aguirre Cristian B, Seeb Lisa W, Seeb James E, Cádiz María I, Musleh Selim S, Arismendi Ivan, Gajardo Gonzalo, Galleguillos Ricardo, Gomez-Uchida Daniel
Genomics in Ecology, Evolution and Conservation Lab (GEECLAB) Departamento de Zoología Universidad de Concepción Concepción Chile.
Laboratorio de Genética y Acuicultura Departamento de Oceanografía Facultad de Ciencias Naturales y Oceanográficas Universidad de Concepción Concepción Chile.
Ecol Evol. 2017 Nov 28;8(1):273-285. doi: 10.1002/ece3.3574. eCollection 2018 Jan.
Different pathways of propagation and dispersal of non-native species into new environments may have contrasting demographic and genetic impacts on established populations. Repeated introductions of rainbow trout () to Chile in South America, initially through stocking and later through aquaculture escapes, provide a unique setting to contrast these two pathways. Using a panel of single nucleotide polymorphisms, we found contrasting genetic metrics and patterns among naturalized trout in Lake Llanquihue, Chile's largest producer of salmonid smolts for nearly 50 years, and Lake Todos Los Santos (TLS), a reference lake where aquaculture has been prohibited by law. Trout from Lake Llanquihue showed higher genetic diversity, weaker genetic structure, and larger estimates for the effective number of breeders () than trout from Lake TLS. Trout from Lake TLS were divergent from Lake Llanquihue and showed marked genetic structure and a significant isolation-by-distance pattern consistent with secondary contact between documented and undocumented stocking events in opposite shores of the lake. Multiple factors, including differences in propagule pressure, origin of donor populations, lake geomorphology, habitat quality or quantity, and life history, may help explain contrasting genetic metrics and patterns for trout between lakes. We contend that high propagule pressure from aquaculture may not only increase genetic diversity and via demographic effects and admixture, but also may impact the evolution of genetic structure and increase gene flow, consistent with findings from artificially propagated salmonid populations in their native and naturalized ranges.
非本地物种传播和扩散到新环境的不同途径，可能会对已建立的种群产生截然不同的种群统计学和遗传学影响。彩虹鳟（）最初通过放养，后来通过水产养殖逃逸，多次被引入南美洲的智利，这为对比这两种途径提供了一个独特的环境。利用一组单核苷酸多态性，我们在智利最大的鲑鱼幼鱼生产地近50年的兰基胡埃湖以及一个依法禁止水产养殖的参考湖托多斯洛斯桑托斯湖（TLS）中，发现了归化鳟鱼之间截然不同的遗传指标和模式。与来自TLS湖的鳟鱼相比，来自兰基胡埃湖的鳟鱼表现出更高的遗传多样性、更弱的遗传结构以及对有效繁殖者数量（）的更大估计。来自TLS湖的鳟鱼与兰基胡埃湖的鳟鱼不同，表现出明显的遗传结构以及与该湖两岸记录在案和未记录在案的放养事件之间的二次接触一致的显著距离隔离模式。多种因素，包括繁殖体压力的差异、供体种群的来源、湖泊地貌、栖息地质量或数量以及生活史，可能有助于解释两湖鳟鱼不同的遗传指标和模式。我们认为，水产养殖带来的高繁殖体压力不仅可能通过种群统计学效应和混合增加遗传多样性和 ，还可能影响遗传结构的进化并增加基因流，这与在其原生和归化范围内人工繁殖的鲑鱼种群的研究结果一致。
