Native fi sh populations are decreasing due to several impact factors of the environment. In order to address this problem, several actions, for example stocking, have been accomplished. However, if these actions are undertaken without any scientifi c support, their effi ciency is low, and they can cause loss of genetic diversity in the populations, and irreversible impacts in the next generations. For this reason, the use of molecular markers to assess diversity through genetic monitoring, can contribute to the conservation of the icthyofauna.