Strong genetic difference of Eurasian perch Perca fluviatilis from two Alpine lakes used as founder populations for farming
In this study, the genetic diversity of Eurasian perch Perca fluviatilis was compared between two lakes, Lake Geneva and Lake Neuchâtel, which are only separated by 50 km and often used to establish the broodstock for farming. Perch were sampled in six localities in Lake Geneva, and two localities in Lake Neuchâtel. Analyses were performed using twelve microsatellites in June 2012 (spawning period) and September 2012 (early autumn). Results revealed that perch populations in Lake Geneva were genetically different than those of Lake Neuchâtel. Genetic diversity of perch in Lake Neuchâtel (mean number of allele A = 6.91, allelic richness Ar = 5.19 and observed heterozygosity Ho = 0.607) were significantly higher than for perch in Lake Geneva (A = 6.08 Ar = 5.86 and Ho = 0.416). Some private alleles were present and characterize each lake population. According to FST-pairwise estimates, populations of the two lakes were significantly different. Some hypotheses that may explain this difference are discussed: the nature of the watershed and the anthropic pressures, as fishing pressure and aquaculture practices. Even at a fine-local scale, the choice of the origin of a wild population influences the initial genetic variability introduced in the farming system at the first step of domestication.