Heteromorphic sex chromosomes in three species of the genus Leporinus (Pisces, Anostomidae)

Abstract
The present paper describes three cases of heteromorphic sex chromosomes in fishes of the genus Leporinus (Anostomidae). An XX/XY type was found in Leporinus lacustris and a ZZ/ZW type in L. silvestrii and L. obtusidens. These facts agree with the observations of Ebeling and Chen (1970), who suggested that heterogamety evolved not once but many times among the teleosts.