Genetic basis of Colossoma macropomum broodstock: Perspectives for an improvement program

Tambaqui, Colossoma macropomum (CUVIER, 1818), is the most farmed fish in Brazil. Endemic to the Amazonas and Orinoco basins, it is currently raised in all Brazillian regions. The lack of basic genetic information on tambaqui broodstock has been one of the problems of improvement programs in the species. The goal of this study is to provide information on the genetic basis of tambaqui broodstock from six fish farms located in three different regions of Brazil for application in improvement programs. Thus, genetic analyses were conducted using 15 microsatellite loci. We observed that the broodstock of Biofish (NortB), Prosperidade (NortP), and Tajá (NortT) presented loss of genetic variability. However, their genetic diversity values are higher when compared with the broodstock from the AquaBrasil (improved, NortA) project, Brumado (SoutB), and Departamento Nacional de Obras Contra a Seca (DNOCS) (NorthD), respectively. Furthermore, the broodstock of DNOCS needs to be renovated or increased, and the AquaBrasil individuals need to be better evaluated to verify the improvement achieved in the improvement program. Thus, aimed at the improvement of tambaqui production in the fish farms analyzed, we recommend increasing the population size of the broodstock to avoid inbreeding.