The results of the study on several immuno-biochemical parameters of blood serum and liver of Engraulis encrasicholus ponticus (L. 1958) and Sprattus sprattus phalericus (L. 1958), that inhabit the Caucasus coastal waters of the Black Sea with various anthropogenic loads are described. The antimicrobial properties of serum, the content of non-specific immune complexes, in the liver antioxidant activity were studied. It was determined that the ratio of immunodeficient individuals was much higher in samples from the polluted areas than in samples from the clean ones. The fish sampled in areas of high anthropogenic load contained higher contents of products of lipid peroxidation and immune complexes, as well as lower values of antioxidants.

The results of a comparative analysis of some blood serum immune-biochemical indices of bream that inhabits lake Nero and the Rybinsk Reservoir are reported. The following indices were investigated: anti-microbial properties: proportion of immune-deficient animals, common lipids level and their fractional composition, content of malondialdehyde and antioxidant activity. Unlike fishes from relatively clean waters, fishes from ecologically unfavorable areas show low immune status, alterations in lipid metabolism and increased free radical oxidation.

Investigation results are reported on immunobiochemical indices in carassius carassius at a chronic exposure to sub-lethal Zink ions concentrations. In blood serum and liver, the following characteristics were investigated: antimicrobial properties, proportion of immune- deficient animals, content of non specific immune complexes, common lipids level, content of lipids peroxidation products and antioxidant activity. The relation between magnitudes of indices under investigation in fishes and the duration of their presence under experimental conditions is shown.

Results of the long-term researches on variability of humoral factors of natural immunity of bream (Abramis brama L.) of the Rybinsk reservoir over the fattening period at various biomasses and composition of forage objects are analyzed. Connection of functional characteristics of immunity and macrozoobenthos' abundance and structure is established. Breams, caught over low abundance of the benthic organisms, were characterized by high portion of immune-deficit specimens and moderate values of antimicrobial properties of blood serum.

Paper deals with antimicrobial properties of the blood serum, content of immune complexes and lipid peroxidation products in the scorpion fish Scorpaena porcus, inhabiting coastal zones of the Black Sea with different degree of anthropogenic pollution.

Проведено исследование антимикробных свойств сыворотки крови, содержания иммунных комплексов, общих липидов, продуктов перекисного окисления липидов у леща Abramis brama, обитающего в р. Кубани в районах с разным уровнем антропогенного загрязнения. Показана зависимость величин исследованных признаков от места обитания рыб.