THE USE OF FISH SCALE EPITHELIA IN NONDESTRUCTIVE METHODS OF KARYOTYPING OREOCHROMIS-NILOTICUS L AND CYPRINUS-CARPIO L FOR EXPERIMENTAL GYNOGENETIC STUDIES

Metaphase figures suitable for karyological investigations in fish wer e produced by the use of non-invasive and non-destructive methodologie s. Large numbers of dividing scale epithelial cells were obtained by t wo methods: first, scale epithelia of Oreochromis niloticus were cultu red for 22 hours at 28-degrees-C, and second, scale epithelia of Cypri nus carpio were used without culturing after the addition of a metapha se inhibitor. These techniques gave typical karyotypes in control carp and tilapia and confirmed absence of paternal (carp) chromosomes in g ynogenetic tilapias.