Genetic variability of broodstocks of Tambaqui (Teleostei – Characidae) from the northeast region of Brazil

The objective of this experiment was to evaluate the genetic diversity within three Tambaqui broodstocks (Colossoma macropomum). Eight primers were used to analyze 67 individuals collected from three fish farming in the municipalities: Porto Real do Colégio – Alagoas (PRC), Araujo 1 – Sergipe (AR1) and Araujo 2 – Sergipe (AR2), in Brazil. Differences in the frequencies of 88 fragments and four exclusive fragments in PRC were found. High polymorphism values (from 54.38% to 64.38%) and Shannon´s index (from 0.33 to 0.37) were observed. The AMOVA showed that high variation is within each broodstock. The identity and the genetic distance among the groups ranged from 0.845 to 0.975 and from 0.025 to 0.156 respectively, and the shortest distance was found in the groups PRC x AR1 and PRC x AR2. The genetic differentiation ranged from lower to higher (Fst = 0.03 and 0.178) as well as the migratory number per generation (Nm = 5.07 to 12.8). In general, the broodstocks had high intra-population variability, and high differentiation and genetic distance within themselves.