Podrugina A. Tolerance and potential of Gammaridae to the effect of abiotic and biotic factors under cultivation in regulated systems

The dissertation is focused on the determination of the physiological tolerance ranges and adaptive potential of crustaceans Gammaridae to the effect of abiotic and biotic factors, determination of optimal conditions for their growth and development, with the purpose of controlled reproduction in operated systems. One of the most important factors that specify the peculiarities of adaptive reactions of gammarids both in natural and artificial conditions is the water temperature, since it regulates the expression of essential living functions of aquatic animals. Further increasing of water temperature to 27-30 °С decreases the reproduction rate of Dikerogammarus haemobaphes (Eichwald, 1841), Chaetogammarus ischnus (Stebling, 1898) and Pontogammarus robustoides (Sars, 1894), and terminate reproduction of Dikerogammarus villosus (Sowinsky, 1894). Temperatures over 28 °C can be considered as critical for these species reproduction.It is shown that the formation of the thermoresistance of gammarid is multidirectional and depends on the biological features of the species and mode of factor action: static, dynamic, cyclic modes. It is found that Ch. ischnus and P. robustoides exhibit high resistance to ammonia nitrogen in an aqueous medium, which is one of the limiting factors in cultivation in regulated systems. On the basis of experimental research, the technological scheme of Ch. ischnus cultivating in operated systems was developed.