Extended Abstracts: Environmental biology 291 fifth of normal, testosterone concentrations to a third, and egg water content increased.The frequency of degeneration of ripened eggs and milt sampled at different sites on the migration route increased from 6% in 1978 to 20-30% in 1993-1996. These gonadal anomalies compromise success of artificial reproduction. There are some data indicating that part of the spawning stock remains in the sea because of disturbances in hormonal metabolism. Altogether, degenerative features were manifest in 60% of the spawning population in 1993-1996. Recently, deviations in biochemical parameters (the content of cytochromes P450 and b,, vitamins A and E, gonadal hormones and other indices) have been observed that indicate chronic toxic effects. Analysis of interrelations between reproductive quality, biochemical changes and accumulation of a wide spectrum of toxicants in the fish has shown that lead, mercury and metabolites of DDT play the main role in causing gonadotoxic effects.

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Introduction. The material shows halophiles bacteria R. Psendomonas the water’s microbiota and the pikeperch in spring and autumn. The attachment of Pseudomonas isolated from these habitats, certain Delta areas has not been identified. Materials and methods. 190 “water” strains and 720 ones isolated from fish were experimentally tested. In meat-peptone broth (MPB) with 3.0, 7.0, and 10.0% NaCl content, daily cultures of analyzed bacteria were sown, incubation of which was carried out at 37 0 C, and the results were taken into account after 24 and 48 hours. Results. There were no significant differences in halophilicity in the analyzed strains, except for the autumn season, especially in 10.0% salt solution. Among the isolated pseudomonads, the maximum halotolerance in both biotopes was observed in P. fluorescens and P. alcaligenes in P. putida. Halophiles strains of Pseudomonas that infect the water and fish had seasonal cycles. A slight decrease in the halophilicity of pseudomonades persistent in water and fish only at concentrations of 3.0 and 10.0 mg/l from spring to summer (1.1-1.2 times), and their significant rise in autumn (1.5 and 1.4 times) in the salt concentration of 3.0 mg/l. In the tested strains in spring and autumn, increased salt tolerance values were noted, which was determined by the hydrological and hydrochemical features of Delta waters and the “transfer” of bacteria in the body of walleye during its migration from the sea to the river. Conclusion. Analysis of long-term material showed high halophiles studied strains of pseudomonad, indicating that their sanitary and epidemiologic danger, and the ability to remain viable in salted fish products

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The article presents the results of a study of halotolerance in aeromonads isolated from 447 specimens of perch (Sander lucioperca) and 375 water samples in areas of its habitat in the delta of the Volga River. They were subdominant in the microbial landscape of these biotopes. There were no significant differences inoculation aeromonads found in various parts of the delta. Their halotolerance was studied by means of inoculation of daily pure cultures of meat--peptone broth with 3, 7 and 10% of sodium chloride content and incubation at 37◦C. All the studied microflora of this spieces was established to have significant indices of halotolerance with a predominance in water isolates. Whereby in cases of 3.0 and 7.0% NaCl concentrations were 2.2 times more and in the 10.0% NaCl solution with water and fish strains had similar indices, showing them to be of “marine origin”. Among isolated aeromonads, shattering the water and fish most halophilic strains of A. hydrophila and A. sobria, and halophobic strains were presented by A. caviae. As a rule, water strains had stability indices above in the average of 1.3 times higher than fish ones. Epidemiologically important strains of A. sobria were isolated from water more frequently than from fish, whereas A. hydrophila was isolated as in water as in fish at the same level. Halotolerance of isolated aeromonads in hydroecosystems of the delta of the Volga River had seasonal specificity and dynamics. The gain in halotolerance in aquatic strains of aeromonads in spring and autumn was caused by natural and climatic processes and the elevation in the salinity of delta waters. Enhanced halophilic strains of fish in these seasons is determined by their migration with fish, because in seasons pike migrates from the sea to the river ecosystem.