“…Although our results support the notion of multiple introductions, this should be interpreted with caution as several factors may be responsible for this pattern, including an unsampled source population, postinvasion genetic drift, insufficient marker resolution and admixture in the source population (Chown et al., 2015; Gray et al., 2014). Given that hatcheries make use of artificial selection techniques to enhance species production and abundance (e.g., Aprahamian, Smith, McGinnity, McKelvey, & Taylor, 2003; Lamaze et al., 2012), it is possible that the introduced M. dolomieu were of admixed or hybrid origin, as has been reported for stockings of S. fontinalis (Cooper, Miller, & Kapuscinski, 2010; Lamaze et al., 2012; Sloss, Jennings, Franckowiak, & Pratt, 2008). …”