[Distribution and cytogenetic features of triploid male goldfish from Azov basin]

When studying uni-bisexual goldfish (Carassius auratus gibelio) populations in the Azov basin in 1995-2000, we found triploid males, which constituted 2.5%, on average, of the total numbers of studied samples. The areas of nuclei of erythrocytes of triploid males were, on average, 1.35 times those in diploid males. At the same optical density of DNA, the sizes of mature spermatozoon heads in triploid males were, on average, 1.8 times smaller than in diploid males, as follows from the data obtained in 1966. The results of similar studies carried out during the period of natural spawning activity in 1997-1999 suggest that the sizes of spermatozoon heads suggest that the sizes of spermatozoon heads in triploid males were, on the contrary, 1.5 those in diploid males. Triploid males were characterized by mosaicism of spermatozoon size and chromosome mosaicism in somatic cells. Electrophoretic analysis for the locus of transferring confirmed the triploid status of this genetic group. The results of comparative crosses of goldfish with different ploidy suggest a high fertilizing capacity of triploid males, as well as normal viability of their progenies. A distinct positive correlation (r = 0.73) was found between the numbers of triploid females and triploid males in mixed di-triploid populations. No significant correlation was found between males and females within di- or triploid populations.