The data describing the supply and demand for fish products, trends in the development of the fish industry of the republic for 2010 - 2016, the ratio of own industrial fish breeding and imports and the prospects for own fish production are given.

Physiological status of junior replacement groups of two lines of selection mirror carp was assessed through the use of biochemical survey of blood serum by major parameters: content of crude protein, glucose, cholecterol. There were ascertained the families of selection mirror carp with flactuations of protein, cholesterole and glucose content during hibernation residing within the limits of optimum values.

In the issue of surveying the content of crude protein, cholosterole and glucose in blood serum with underyearlings and yearlings of the carps pertaining to various breeds of both belarussian and foreign selection there were ascertained some changes in physiological and biochemical indicators with underyearlings in comparison with yearlings. There were specified some advantages specific for slip incorporating the mix of mirror Isobelino carp amongst belarussian lines and Sarboyan carp amongst imported breeds.

In the issue of comparison assessment of the composition indicative to body of underyearlings and yearlings of carp belonging to various breeds there were ascertained the breeds with some advantages by the amount of three indicatives (content of dry substance with underyearlings and yearlings and its change in hibernation).

The article presents the effect of complex assessment of fishery indicators of junior replacement stock of selection families of mirror carp. There are ascertained the families being most perspective in terms of selection.

The article provides the effects of the comparison assessment performed on fishery indicators of underyearlings, yearlingsand two-year old carps belonging to various breeds from the collection stock of “Izobelino”, Selection & Production Site, incorporating lines of Belarussian selection and imported breeds of the fourth generation grown in the Republic of Belarus.

There is suggested biological method of purifying the contaminated water diverted from fish breeding farms by means of applying microbial substance «Biovir»

There are assessed temperature and chemical conditions of the waters in irrigation system. There is suggested to consider the said type of water reservoirs as the perspective one in terms of fish breeding.

The paper presents the research results of low intensity optical radiation effect on the rainbow trout larva in aquaculture hatchery. The radiation source was laser-optical device «Stronga» (red spectrum, λ = 630 nm) for five days to 20 minutes a day with the power density 3.0 mW / cm2. During the research out regular check size and weight of larva. The results show, that laser-optical device «Stronga» has a stimulating effect on the rainbow trout larva. The stimulating effect by the 31st day of observation increased to 33.3% for larva weight and from 5.1 to 11.0% for larva size (depending on the size indicator).

Examination of a sterlet and the Russian sturgeon for the purpose of assessment of their physiological state is conducted by method of the morphological analysis of biological liquids (a edge dehydration). For verification of the obtained data the key hematological and biochemical indicators of blood of fishes were defined. The informational content of a method of a regional dehydration at assessment of a physiological condition of fish and her adaptation opportunities is established.

To improve the efficiency of cultivation of sturgeon juveniles for artificial reproduction purposes it is necessary to reduce losses in the initial stages of biotechnical process. One way of solving the issue is to create optimal conditions for the formation of food resources and the effective use of the biological productivity of the rearing ponds fish hatcheries. The article discusses the results of studies on nutrition and growth of stellate sturgeon in the rearing ponds in early and traditional time filling them with water. It is shown that the flooded with nursery ponds for 2 weeks earlier increases the biomass and species composition of forage that improves nutrition and growth of juveniles of stellate sturgeon, and improve their physiological status.

The article shows the current state of the raw material base for the production of mixed fodders for freshwater fish. New possible types of raw materials, such as oat grain, cereal flour, fish hydrolyzate, hemoglobin flour are considered. The advantages of production of extruded mixed fodders over granulated fodders are considered.

Comparative characteristics of different varieties of lupine and beans are given. As a result of the conducted researches, perspective varieties of beans and lupine have been established for further use in the production of mixed fodders for fish.

In this article are presented the results of the protein digestibility of the fodder protein additive "Extra" by the fingerling, two- and three-year-old carp. It has been established that the protein digestibility of the fodder additive by the age-old carp is on a par of digestibility of meat-and-bone meal.

It is demonstrated that recently the dynamic of total catch and species structure of commercial catches for has been determined significantly by restructuring of fish industry in the Republic of Belarus and targeting to the catch valuable species of fish. It is observed that the bream (Abramis bram) is turning into the major native species in terms of catch volumes with commercial catch amounting currently to over a quarter of the total fish catch and actually is comparable with the aggregated catch of all stocked species.

A brief overview of the Caspian sea, its geographic status, hydrological conditions, information about his conditional geographical and management unit. The General history of oil production in the Caspian sea, listed new gas and oil fields on the shelf of the Northern and middle Caspian. Given the modern characteristics of oil and gas fields in the Eastern part of the North Caspian sea (Kazakhstan). We consider the environmental situation prevailing currently in the reservoir, the factors that characterize it, the problems and their solutions at the present stage.

During the development of oil and gas fields on the shelf of the seas, the increase in the content of petroleum products in the marine environment, as a rule, leads to deterioration of the forage base for fish, the depletion of species composition, larval forms of many fish are under threat. As a result of sharply reduced the number of fish in their body and the pathological changes are established, their physiological state is characterized by functional abnormalities of varying degrees. The article presents data on the content of heavy metals in sediments in the spring and autumn of 2016

Research was carried out on the subject of species richness and the taxonomic structure during the entire growing season. Densities levels, biomass and dynamics of zooplankton development in three feeding carp ponds with dependent water supply of the fish factory «Beloye» in the Zhitkovichsky district of the Gomel region were assessed. Ponds are similar in terms of areas, densities of growing a year old carp and the volume of introduced mixed fodder. As a result of the research, was established that as a result of the transfer of organic matter in the ponds of the cascade in the Lower Pond, the level of development of zooplankton is three times higher than in the Upper Pond. The fish production of the Lower Pond was also 25% 

In article results of researches of a fish fauna of a cluster Zabelovsky of the national natural reserve Bastak (Jewish Autonomous Region, Russia) are considered. Based on the analysis of materials of field surveys of 2001 - 2017 data on dwelling are provided in reservoirs of a cluster of predatory fishes, representatives of a flat fish fauna of the basin of the Amur River. 18 species of the fishes living in a cluster which are obligate or optional predators are revealed. Questions of a role of predatory types in trophic circuits of an ecosystem of a cluster are considered.

The article provides data on the species composition of alien species of helminthes in introduced fish species in pondfish cultures (pond fish farms) and natural reservoirs of Belarus. Invasive species of helminthes that cause substantial damage to the fish husbandry are identified, that leads to the death of introduced fish species in pondfish cultures (pond fish farms). Based on the evidence found and literature data analysis, the main trends in the adaptation of alien helminth species in the reservoirs of Belarus are noted: the widespread of a number of invasive species of parasitic worms in the populations of introduced species, as well as the development of new hosts among the native fish species.