Evaluation of functional state of crayfish Pontastacus leptodactylus in normal and toxic environment by characteristics of their cardiac activity and hemolymph biochemical parameters

Abstract

The work deals with study of basic characteristics of cardiac activity (HR and stress-index) and hemolymph protein parameters in the crayfish Pontastacus leptodactylus. The main criteria of the crayfish selection are developed for formation of the animal reference groups available for subsequent toxicologic experiments. The action of a model toxicant, hydroquinone (often present in waste water), at a concentration of 1 g/l on parameters of the crayfish cardiac activity at various exposition time, its effect on circadian cardiac activity and on the hemolymph total protein were studied. At its short-term exposure, hydroquinone produced a temporary increase of HR and stress-index, but had no marked effect on the total protein parameters in hemolymph. At long action (for one day), hydroquinone led to a considerable tachycardia, disturbance of the circadian cardioactivity and to a decrease by 40% of the hemolymph total protein. In 50% of cases the toxicant caused death of the animals either in the course of its action or at period of washout from the toxicant. Mechanisms of the toxic action of hydroquinone at various levels of organization are discussed.