SEASONAL AND SEXUAL FEATURES OF THE TRACE ELEMENTS COMPOSITION OF THE BODY OF the river long-toed CRAWFISH ( <i>PONTASTACUS LEPTODACTYLUS</i>)
The trace element composition of the river long-toed crawfish ( Pontastacus leptodactylus ) of the Delta of the Volga river is studied in relation to the season and sex of the organisms. The specific features in the degree of utilization of the various organs of the river long-toed crawfish of such essential elements as zinc, copper, manganese and cobalt and conditionally essential - nickel and lead are defined. It was found that the copper for the crawfish body is an element of strong accumulation, especially for gills, liver, muscle and carapace. Zinc is on the second place of the accumulation in the body of crawfish. Nickel, manganese, lead and cobalt have a coefficient of biological absorption less than one. Seasonal features of the distribution of trace elements in the body of crawfish are characterized with increased disposal capacity in relation to copper and manganese in summer, zinc, nickel - winter and cobalt - fall. It was found that all the studied elements, except copper, are mostly concentrated in females in comparison with males.