Biological peculiarities of the body of juvenile sturgeons (Acipenseridae Bonaparte, 1831) under the action of synthetic and organic immunostimulators

Purpose. To analyze the productive-biological and biochemical parameters of sturgeon larvae fry under conditions introduction synthetic (Levamisole) organic (Chitosan) immunostimulants into their diet. evaluate effect supplements on stability homeostatic processes based analysis enzyme activity. Methodology. The study was carried out juvenile hybrid besters (♀ Huso huso х ♂ Acipenser ruthenus) sterlet (Acipenser (BSS). Larvae were fed with Artemia nauplii, which transfer after a six-hour enrichment in respective solution. Pre-larvae, reared RAS at Lviv Research Station Institute Fisheries National Academy Sciences Ukraine. During cultivation, main productive studied, included: weight, body length, growth rates, mortality, output from each stage cultivation. activity α-amylase determined by Karavey’s method. Alanine aminotransferase Reitman–Frenkel’s Alkaline phosphatase reaction phenylphosphate. Gamma-glutamyltranspeptidase L-gamma-glutamyl-p-nitroaniline. All data statistically processed using Statistica 6.0 MS Excel. Findings. Addition Levamisole to diet during first week exogenous feeding had positive larvae. average weight experimental fish group No. 1 increased 3.96 times, 9% higher than control values. In 2, consumed Chitosan, no significant difference found compared group. Average daily 24.9% 20.7% 22% 3, served as control. After 21 days experiment, sturgeons 1, Levamisole, 0.794 g, exceeded values 50.5%. juveniles 2 0.661 25.28% rates 9.3% 12.1% 11.3% 3. short-term digestive enzymes period shown. for action both Chitosan 88.2 91.4%, respectively. transferases (AlAT, LF, GGTP) tissues internal organs confirmed strengthening nonspecific resistance short due activation transport dephosphorylation transamination. addition, none indicated impairment homeostasis. Originality. advisability raising has been demonstrated. these evaluated. Practical value. obtained results will be useful improving technology early rearing fry. application acquired knowledge allow reducing mortality critical periods cultivation non-specific immunity valuable species. Key words: sturgeons, enrichment, resistance, immunostimulants.