Genetic variability of larvae and fingerlings of Piracanjuba (Brycon orbignyanus)

ABSTRACT

The objective of this study was to evaluate the genetic variability of Piracanjuba larvae and fingerlings in restocking program. A total of 180 three-day Piracanjuba larvae and 90 three-month-old fish were sampled. Five microsatellite loci were evaluated, which produced 19 alleles. There were no rare alleles or loss of alleles over the period. The observed heterozygosity was higher in larvae compared to fingerlings. There was a deviation in Hardy-Weinberg equilibrium in most loci in both groups. The inbreeding coefficient was positive in both groups, with the average of the fingerlings superior to the larvae. The excess heterozygotes were significant in the Stepwise Mutation Model for the fingerlings, indicating the possibility of a recent bottleneck effect. Despite the adequate genetic variability found, the values of the inbreeding coefficient and the possibility of bottleneck effect in the fingerlings show the need for constant genetic monitoring of these stocks prior to release into the environment.

Keywords:  conservation; bottleneck effect; genetic monitoring; restocking