Evaluation of the effect of different levels of Pontogammarus maeoticus extract on growth indices, carcass composition and mucosal safety ofRutilus kutum, Kamenskii, 1901

In this study, the effect of diets containing different levels of Pontogammarus maeoticus extract as natural nutrient attractant was investigated on growth indices, chemical composition and mucosal Immunity of Rutilus kutum. For this purpose, fish with an average weight of 0.35±0.067 were stored in 100L fiberglass tanks containing 30 liters water with a density of 20 fish per tank for eight weeks. To perform this study, Gammaridae extracts were mixed with distilled water in three concentrations: 1:25 (25%), 1:50 (50%), 1:75 (75%) and two percent of each dilution was added to manual meals before each feeding. This experiment was performed as four triplicated treatments. Larvae were fed four times a day. At the end of the culture, growth indices such as: mean body weight gain, specific growth factor, food conversion ratio, survival, chemical analysis of carcasses and some mucosal immune parameters including; lysozyme, immunoglobulin, alkaline phosphatase and protease were studied. The results showed that although growth factor and carcass analysis were improved in all treatments (25%), this increase was not significant compared to the control (p>0.05). All Mucus immune factors significantly increased in all treatments compare to control (p<0.05). The result of this study showed that the Gammaridae extract had no significant effect on the improvement of growth performance, but increased the immunity of Rutilus frisii in culture conditions.