Peciliarities of Hormonal Regulation of Growth Rate and Generative Functions of Fishes under Increased Anthropogenic Influence

Abstract

The hydrochemical parameters, the production and destruction of organic substances in different areas on the Ros and Protoka rivers were studied. Nearby the Horodyshche vil. (Ros River) and Pishchana vil. (Protoka River), concentration of ammonium nitrogen exceeded control values 2-5 times, nitrites - 1.5-2.5 times, nitrates - almost 3.0-5.8 times (as control the Ros River in the Olexandria dendrological park was used). Water of the considered sections was significantly contaminated by pesticides (chlorpyriphos) from the adjacent territories. Elevated content of nutrients in water conditioned intensive production processes (Pishchana vil.), whereas high chlorpyriphos content (Gorodyshche vil.) along with significant concentration of chlorpyriphos (Gorodyshche vil.) suppressed organic matters' production. The water quality deterioration and presence of the toxic contamination caused decrease of the size-mass parameters of common ruff, river perch and common rudd, mainly owing to decrease of somatotropin content in blood. The gonadosomatic index of perch and rudd females from contaminated water bodies increased, whereas in males it decreased as compared with the control. The relative and absolute fertility of rudd increased along with increase of the contamination degree. The females' fertility growth under the unfavorable conditions was associated with increase of the estradiol content in blood. The perch and rudd males were characterized by decrease of the gonadosomatic index along with decrease of the testosterone content in blood. Decrease of size and mass parameters and increase of the females' fertility is an adaptive response aimed at the population maintaining and higher vitality under toxic environment. These processes are provided by hormonal regulation of metabolic processes.