Comparative results of rearing pure species and hybrid forms of the Siberian and Russian sturgeons

Abstract

In the paper, rearing results and comparative assessment of interspesific hybrids and pure species of the Siberian sturgeon Acipenser baerii (Brandt, 1869)and the Russian sturgeon Acipenser gueldenstaedti (Вrandt, 1833) have been provided at various stages of ontogenesis by combinated cultivation under RAS conditions and in an industrial uniflow tank farm. Investigations were carried out at the “Konakovski” department of the Branch on Freshwater Fisheries FSBSI “VNIRO” (VNIIPRKh). To obtain the experimental material breeders were used of the Siberian sturgeon from the sixth domestication generation and of the Russian sturgeon from the third one. Fish fry, switched to mixed feeding ongrowing and further rearing, were cultivated under production conditions in normal technological mode and separately from each female using different granulated mixed feeds (BioMar firm) of different recipes. Up to 41 day-age fish were reared in RAS, further in race-ways and tanks of the shop with uniflow water-supply. The middle water temperature was 16ºC during the all period of experimental works (557 days). Best results of the mass accumulation showed interspecific LS×RS hybrids, at the second position seemed to be RS×LS hybrids. Pure species of the Siberian and Russian sturgeons showed practically similar middle weights to the end of the experimental stage. As a result of the histological analysis, it has been ascertained that gonads of pure species of one-year-old Siberian and Russian sturgeons and their hybrids had comparatively the same picture of sex cells development, but some advantage possessed the Siberian sturgeon and LS×RS hybrid. Thus, malesʼ cysts and femalesʼ nests of one-year-old fish show multiple mitotic divisions of sex cells (spermatogonia and oogonia) what corresponds with the first stage of gonades maturity in males and the first one and the beginning of the second ones in females.