DOI: https://doi.org/10.1515/vzoo-2015-0011
Karyotype analysis of males and females of two Viviparid species Viviparus viviparus Linnaeus, 1758 and V. contectus (Millet, 1813), shows differences in their karyotypes in the absence of heteromorphic pairs of chromosomes. Th is indicates an epigamous mechanism of sex determination.