EXPERIENCE OF THE REARING OF SO-IUY MULLET <i>PLANILIZA HAEMATOCHEILA </i>FINGERLINGS IN POLYCULTURE WITH THE EUROPEAN CARP <i>CYPRINUS CARPIO </i>IN FRESHWATER PONDS
E. V. Gorbenko, A. A. Pavlyuk, S. G. Sergeeva, Maria Grinchenko, A. P. Nagornaya
Abstract
The results of the experiment on the rearing of so-iuy mullet fingerlings in polyculture with the European carp in the ponds with decreased mineralization, which has been conducted at the facilities of Rogozhkino Fish Farm, are presented. The so-iuy mullet juveniles were obtained artificially in a hatchery of the research facility “Zavetnoe” and reared on artificial feeds of two different formulations. In the first mode of rearing, the average weight of juveniles was 1.68 g, and in the second one it was 3.49 g. At the further stages, the juveniles were separated into different ponds based on the feeding mode. The juveniles in these ponds were reared under the controlled hydrochemical and hydrobiological conditions. The species composition of the zooplankton community was typical for pond ecosystems. In the experimental ponds, the biomass of the zooplankton on which the juveniles fed was low—2.2 g/m3 on average. Dietary analysis of the so-iuy mullet juveniles has shown that the detritus content in a food bolus was no less than 30 %. The dynamics of cultivation, biological, physiological, and biochemical parameters of the juveniles have been identified for different modes of rearing. The result obtained with the first mode of rearing was positive; growth characteristics and physiological status of the juveniles were on the normal level for the individuals of such age growing in natural water bodies. The quality and growth rate of the so-iuy mullet juveniles reared in the second mode were satisfactory; total lipid content in the tissues was relatively low. These results reveal the possibility of rearing healthy so-iuy mullet juveniles in fresh water. It is conducive to stock the freshwater bodies with the fingerlings which weight does not exceed 3–4 g; the juveniles of higher weight gain reared on artificial feeds adapt to the aquatic environment of a water body after their transition to the natural feed considerably longer.