Triple hybrids obtained by artificial hybridization of the Russian sturgeon Acipenser gueldenstaedtii with the hybrid of the starred sturgeon A. stellatus and the great sturgeon A. huso (Acipenseridae): The kind of inheritance of some morphological characters and fertility of the parental hybrid form

Abstract

Results are described of experimental crossing for obtaining of triple hybrids of the Russian sturgeon Acipenser gueldenstaedtii, the great sturgeon A. huso, and the starred sturgeon A. stellatus and of comparative analysis of some quantitative morphological characters in these hybrids, in the progeny of parental species and of reciprocal hybrids of starred sturgeon and great sturgeon. By most investigated characters, in triple hybrids, the states of the paternal species (Russian sturgeon) are inherited, by some other characters-of great sturgeon-the state of starred sturgeon is not inherited. Therefore, on the basis of external appearance, they may be identified as the hybrid of Russian sturgeon with great sturgeon. The observed segregation by the form of gill rakers into paternal, maternal, or intermediate variants leads to a conclusion of nonmonogenous inheritance of a wide form and a conical form of gill rakers in sturgeons. On the whole, the obtained results clearly demonstrate how, due to effects of matrocliny and partocliny, and different combination of dominant and recessive alleles of the genes determining the diagnostic characters, the hybrid individuals may acquire a different extent of similarity and differences from the parental species. The investigated triple hybrids are an interesting example of mutual leveling of divergent traits in the course of combination of different genomes within limits of one closely related Atlantic group of sturgeons. As a result, a certain averaged habitus is formed which might take place also in case of formation of polyploidy species in the process of evolution.