INFLUENCE OF THE INVASIVE SPECIES OF UNIONICOLA YPSILOPHORA (BONZ, 1783) ON THE MORPHO AND IMMUNOPHYSIOLOGICAL INDICATORS OF THE MOLLUSK ANODONTA CYGNEA (L.) OF THE RYBIN RESERVOIR

The effect of the invasive biological species of the Rybinsk Reservoir, the water mite Unionicola ypsilophora (Bonz, 1783) on the morphological and immunophysiological parameters of the infected bivalve mollusks Anodonta cygnea (L., 1758), was studied. The dependence of mollusk infection by water mite on the age, size, fatness coefficient, somatic indices of gills, legs, the content of immune complexes and malondialdehyde, one of the final products of lipid peroxidation, is shown. Indicators of size, total weight, content of immune complexes and malondialdehyde in infected individuals aged 7–10 years significantly exceeded those of uninfected young children 4-5 years old. It is concluded that with age, the level of innate mechanisms of the anti-acaricidal immunity of A. cygnea to water mite decreases, which leads to mass infection and death of older age groups of mollusks. The obtained data can be used to predict the propagation rate of biological invasion of U. ypsilophora in water bodies.</jats:p

Relationship of the average monthly temperature of February and some immunological indicators of the bream in the Rybinsk reservoir in different years

A study of changes in some immunological parameters of fish blood serum depending on the average monthly air temperature was carried out. The studies were carried out on bream aged 3+, with an average weight of 375 ± 30 g and a length of 290 ± 20 cm, caught in the Volga reach of the Rybinsk reservoir. The fish were caught using fixed nets in February for several years and the average monthly air temperature was recorded. The studied fish were sampled from the tail vein. Blood was collected in a dry sterile test tube and kept at room temperature. After blood coagulation and retraction of the clot, the serum was taken with a syringe with a fine needle and transferred to another tube. To assess the state of natural immunity in the blood serum, the level of bactericidal activity and nonspecific immune complexes was analyzed. Based on the data obtained, the number of immunodeficient individuals was determined. Variations of the studied parameters in years different in average monthly air temperature were established. The greatest differences between the indicators were revealed in the years with the highest (2003) and lowest (2006) mean monthly temperatures. The minimum indicators of bactericidal activity were recorded in 2003, and the maximum — in 2006. The highest content of immune complexes and immunodeficient individuals was established in 2003, and the lowest in 2006. The study showed the relationship between an increase in the average monthly air temperature and a decrease in functional activity nonspecific humoral immunity. Based on the data obtained, it was concluded that the temperature factor influences the mechanisms of innate immunity of fish.</jats:p