Studying the Influence of Aquafeeds with Haprin on Morphophysiological Parameters of Sterlet

As part of the study on the effect of the high-protein preparation haprin, introduced instead of fish meal in the diets of young sterlet, we studied the size and weight indices of the body, morphological characteristics of internal organs (organ indices, % to the fish body): heart, liver, intestine, spleen, intestinal length index (%). The paper noted that the microbial synthesis product haprin had a positive effect on sturgeon species that received it as part of feed in the amounts of 25/50/75% instead of fish meal. We found that live weight indices of hydrobionts of the 2nd, 3rd and 4th experimental groups were higher than those of the 1st control group by 5.31, 7.76 and 12.1%. Accordingly, the superiority of the experimental groups 2, 3 and 4 in absolute and relative growth increased and amounted to 23.92, 41.98 and 59.80% and 7.20, 13.54 and 18.82% in relation to the control group 1. In terms of length, width and body height, juvenile sterlet of the control group were 1.16, 3.03, 4.01%; 5.34, 8.90, 12.65% and 8.94, 15.2, 10.4% inferior to their counterparts in groups 2, 3 and 4, respectively. Visual assessment of the condition of parenchymatous organs revealed no deviations from the norm. The liver indices in the 2nd, 3rd and 4th experimental groups were higher than in sturgeon fish of the control group by 0.22, 0.73 and 0.46%. The indices of heart and spleen indices had no significant differences among the experimental groups. Sterlet fed with 25/50/75% haprin instead of fish meal had the most developed intestines, which indicates balanced feed and good nutrient assimilation.