Leporinus friderici is a South American promising species for fish culture. In French Guiana the "morphological species", L. friderici, L. granti, L. lebaili and L. affinis steyermarki are found. Their identification is sometimes difficult on usual criterion. To constitute an initial broodstock of L. friderici from local wild populations, the genetic structure of these species was studied. Fifteen enzyme systems, representing twenty loci, were screened.