Cytological analysis of the reciprocal hybrids between low- and high-chromosome acipenserids, the great sturgeon, Huso huso (L.), and the Russian sturgeon, Acipenser gueldenstaedtii Brandt.

Arefjev VA. Nikolaev AI.

Hybrids between the great sturgeon and the Russian sturgeon in reciprocal crosses are found to exhibit non-intermediate chromosome number, 2n= 167-169, on average. The hybrids are also characterized by sharp increase in variability of the quantitative karyotypic parameters such as diploid chromosome number, bi-armed chromosome number, number of uni-armed and microchromosomes and chromosome arm number. Measurements of erythrocytes and their nuclei confirmed the di-tetraploid relationship of the parental species and non-intermediate pattern of the hybrid genome. Sharp disbalancing of karyotype of both reciprocal hybrids is indicative of high probability of their complete sterility.