Ecological and biological features of river crayfish in the modern conditions of the Kuibyshev reservoir

Abstract

Crayfish are considered as objects of consumption in the modern world. An increase in their share in the production of aquaculture objects is shown. The data on the state of the crayfish population on the territory of the Middle Volga before regulation, after the formation of the Kuibyshev reservoir and at the present time are presented. It was shown that the size-weight and ecological-biological characteristics of long-toed crayfish before regulation and after the formation of the reservoir are similar. The data on the modern size-age characteristics of populations of narrow-clawed crayfish in the Volga-Kama reach of the Kuibyshev reservoir are presented. It is shown that in the catches the basis is made up of three-year-olds 13–15 cm long and weighing about 80–100 g. The equation for the dependence of body weight on the zoological length of river narrow-clawed crayfish in the Volga-Kama reach of the Kuibyshev reservoir: y = 35,588x0,3073. The equation for the dependence of body weight on the commercial length of narrow-clawed crayfish in the Volga-Kama Reach of the Kuibyshev Reservoir: y = 29,409x0,3275. Chemical analysis of narrow-clawed crayfish revealed 12 elements. The following sequences of the content of elements in narrow-clawed crayfish from the Volga-Kama reach of the Kuibyshev reservoir were noted: in the muscle tissue of edible parts — Ca ˃K ˃S ˃P ˃Cu ˃Fe ˃Zn ˃Mn ˃ Br ˃Sr; in shell — Ca ˃Si ˃P ˃S ˃K ˃Sr ˃Ti ˃Fe ˃Mn ˃Cu ˃Br ˃Zn; in entire crayfish — Ca ˃K ˃P ˃Si ˃S ˃Sr ˃Fe ˃Mn ˃Cu ˃Ti ˃Br ˃Zn. In the edible parts of the narrow-clawed crayfish of the Volga-Kama reach of the Kuibyshev reservoir, there are no such hazardous elements as lead, arsenic, cadmium and mercury. Crayfish can be used as a feed additive in feed for aquaculture objects. Crayfish breeding in the structure of aquaculture in the Middle Volga region can become an important component. The development of aquabiotechnology makes it possible to use natural crayfish populations for the tasks of creating industrial crayfish farms.