From river to farm: an evaluation of genetic diversity in wild and aquaculture stocks of Brycon amazonicus (Spix & Agassiz, 1829), Characidae, Bryconinae

Abstract

Brycon amazonicus is widely distributed in the Amazon basin. The species has traditionally been the focus of subsistence and commercial fisheries, and recently has become an important aquaculture species. Aquaculture relies on the removal of individuals from nature which form the basis of breeding stocks. The breeding stocks are often derived from local populations, but equally often are a mix of fishes from different regions or from other aquaculture stations. In this study, we found that B. amazonicus forms just one population in the central Amazon basin, and most animals in the aquaculture stations originated from this group. However, fishes from the Balbina aquaculture station represent another biological group, while the fishes in the experimental station of the Federal University of Amazonas are an admixed group. Fishes of the aquaculture stations are differentiated from each other and from the wild fish. Genetic diversity of the aquaculture fishes was not different from the wild fishes, and thus, inbreeding is unlikely to be a concern. Outbreeding depression, however, should be of concern given the observed levels of admixture in the aquaculture stocks. We conclude the article with recommendations for good practices to minimize the likelihood of inbreeding and outbreeding depression.