In the last decades it has been verified the decrease and extinction of fish several species mainly to impacts generated by human actions. Stocking programs are being used as
conservation methods of the ichthyofauna. However, without a correct genetic and reproductive orientation of the stocks used in these programs, natural fish populations and the
ecosystem can be affected. The objective of the following study was to determine the genetic variability of six fish stocks used in stocking programs, by means of the RAPD
molecular marker. There were analyzed 180 juveniles of three fish species (
Prochilodus lineatus
,
Piaractus mesopotamicus
, and
Leporinus elongatus
) from three fish farms, located in the Rolândia, Andirá,
and Palotina cities in Paraná state, Brazil. The genetic variability values estimated by the percentage of polymorphic fragments and by the Shannon diversity index showed a high
genetic variability between the
P. lineatus and
L. elongatus stocks, due possibly to the founder effect and the reproductive management adopted in each fish farm. It
was determined that low genetic differentiation existed among the
P. mesopotamicus stocks. The results of this study facilitated the correct reproductive and genetic management
of the stocks of each fish farm and the objective orientation of stocking programs, allowing the conservation of the genetic variability, factor of great importance in captivity
environments.
