Temporal genetic variance and propagule-driven genetic structure characterize naturalized rainbow trout (Oncorhynchus mykiss) from a Patagonian lake impacted by trout farming

Knowledge about the genetic underpinnings of invasions—a theme addressed by invasion genetics as a discipline—is still scarce amid well documented ecological impacts of non-native species on ecosystems of Patagonia in South America. One of the most invasive species in Patagonia’s freshwater systems and elsewhere is rainbow trout (Oncorhynchus mykiss). The species was introduced in Chile during the early twentieth century for stocking and promoting recreational fishing and, during the late twentieth century, for farming purposes and is now established or naturalized. We used population- and individual-based inference from single nucleotide polymorphisms (SNPs) to illuminate three objectives related to the establishment and naturalization of rainbow trout in Lake Llanquihue, a Patagonian lake heavily affected by trout farming, by sampling five inlet streams over two seasons (winter and spring). First, we found that significant intra- population (temporal) genetic variance might have playe...