To determine the optimal effect of pH and temperature on the embryological development of Ctenopharyngodon idella

The purpose of this study was to determine the effect of water temperature (18, 26 and 34°C) and pH (5.5, 6.5, 7.5 and 8.5, 9.5) on the incubation and larval stages of grass carp eggs, and also in parallel, it was necessary to determine the optimal values. According to the results of the study, at a temperature above 34°C and a pH level of 5.5 and 9.5 (32.5±0.5), (35±0.001), as well as 18°C and a pH level of 5.5 (22, 5±0.2) and 9.5 (42.5±0.3) showed a decrease in the percentage of hatching egg growth and embryonic development during the incubation period. It has been established that the maximum survival rate of incubated eggs at a temperature of 26°C and pH 7.5 (95% ± 0.002) is favorable for the survival of whitefish in embryonic and postembryonic development. At the same time, the embryonic stages of grass carp development at very low temperatures proceeded very slowly. That is, we have seen that the stages of development are long in time. On the other hand, at higher temperatures it was faster at 34°C. Current results indicate that pH 7.5 at 26°C water temperature is most suitable for egg incubation, while pH 6.5 to 8.5 is best for the growth of Ctenopharyngodon idella eggs.