Some indicators of nonspecific immunity of Bream Abramis brama in reservoirs of the Middle Volga

The study of some parameters of non-specific humoral and cellular immunity was carried out in sexually mature bream individuals living in the reservoirs of the Middle Volga (Kuibyshev, Cheboksary and Gorky). The level of antimicrobial properties and C-reactive protein of blood serum, non-specific immune complexes in blood serum and tissues of kidney, spleen and liver were studied, the share of immunodeficient individuals and phagocytic activity of neutrophils was determined. The highest indices of bacteriostatic activity of serum, average cytochemical coefficient of neutrophils and positive level of C-reactive protein of peripheral blood in the majority of investigated individuals were noted in Kuibyshev and Cheboksary reservoirs. The content of non-specific immune complexes in bream of the Cheboksary reservoir exceeded similar data of fish from other reservoirs. No immunodeficient individuals were recorded in the Gorky Reservoir. The revealed differences are probably related to the impact of different pathogenic factors on the organism of bream.