The comparative characteristic of fishhold characters (average body weight, survival rate, fish productivity, forage quotient) of seven collection species of carp of the fingerlings is represented. The analysis of the resistance of the purebred carp to the inflammation of the swim bladder is given. There are also the results of the mass selection among the different fish species of the fingerlings.

The rate of mass accumulation, survival rate, fish productivity, forage expenses and resistance to such disease as inflammation of the swim bladder (ISB) of 13 complex fish species crossed with mirror squamous integument have been studied. There are particular crosses possesing the increased specific combinational ability with the expressed effect of heterosis according to the indications studied. The most perspective crosses from the fishhold point are recommended for further selection work to form a nucleus of breeding of the mirror carp.

Comparative characteristic of fishhold indicators and extensivity of the disease of the inflamation of the swim bladder of 8 fingerlings mirror carp crosses given. As a result of the complex assessment two crosses perspective for further selection work to create a nucleus of the belarusian mirror carp species are established.

The comparative characteristic of the resistance to the disease of the inflammation of the swim bladder of the carp species of the fingerlings and of the yearling two carp species crossed and pure-line carps has been given. The effect of heterosis and specific combinatinal ability of crosses that are achieved with the participation of the squamous and mirror lines of Tremlyanski carp have been established and their general combinational ability is determined. Crosses of the fingerlings and of the yearling that are resistant to the inflammation of the swim bladder are revealed.

The results of works on efficacy of use of non-traditional fertilizers in form of food-industry waste and by-products in fish-breeding ponds are integrated.

Technological methods of grass carp three year olds rearing in fish polyculture when using herbage were worked up. These methods allow to obtain up to 10 centners per hectare of marketable fish production in second fish-breeding area while lowering its cost price on 30 p.c.

The results of the investigations in different qualitative food usage at a various vegetative season period are represented in the article. The partial replacement of the albuminous food by the carbohydrates food the permits to economize the considerable means without any losses in the carp/s growth.

In article the qualitative and quantitative characteristics of a food of an uneven-age catfish is given at cultivation in ponds conditions.

In article results of researches of wintering of an uneven-age European catfish in прудовых conditions of Belarus are stated. It is established, that wintering can be spent in usual winter ponds in a monoculture or in polyculture with one-age or old age groups of a carp. Optimum conditions of wintering are defined.

Cultivation of uneven-age repair of the European catfish in ponds under the developed specifications allows to receive половозрелых males in three-year, and females – at four-year-old age.

The results of the studies examined the biological characteristics of the larvae of Lena sturgeon when grown in nurseries and determined the optimal parameters for their rearing in the Republic of Belarus. It is established that morphometric parameters of juvenile sturgeon Lena influenced abiotic and biotic factors. Planting density within a certain range can affect the survival of larvae and the dynamics of the size and weight indicators. The most cost–effective and efficient during curing and the transition to artificial feed are stocking densities 6.0 and 2.0 tys.sht./m² tys.sht./m² respectively. Survival in this case is more than 77% and 67%, but the area will require a lot less.

The effective method of studying developments еembryos of fishes is presented. Perspectives of its application in laboratory practice and industrial conditions is shown.

The minimal index of summary changes of structure fish population on the littoral shallow zone river Neman to be detected for the middle part of stream – 0,47 for time from end 80-ties years XX century to a now days; the maximal index to be detected for the upper part of stream – 0,58 for same period.

Some features of the spatial structuring of zooplankton communities of different types of lakes. Possible reasons for the marked differences.

The structure of ichthyocoenosis and meeting of species of the fishes into lakes are examined. Frequency of matching meeting and dependence of volume ichthyocoenosis from some limnological sings are analysed.

The structural adjustment of fish populations of a eutrophic lake when the level of anthropogenic load – the intensity of fishing and fish stocking pond. Noting the relationship of these factors and the mass fraction of individual species in the catches. Possible mechanisms for feedback on the conditions of fishing in the subsequent period.

Established that all of the reservoirs and streams NP of the anglers for the year were caught 240 tons of fish, that in 2,6 times exceeds the catch of fishing. It is shown that the maximum number of fish anglers fished in the winter season (December – March), the least – during the spring ban. Most are caught fish from large lakes, but the relative yield of the many small reservoirs above. Just a catch anglers noted 15 species of fish.

The current state of the ecosystem, the composition of fish fauna And fishery resources of the lake Obsterno. The dynamics of commercial fish Catches, made calculations of commercial stock of wild stocks, provide recommendations for its use.

The paper discusses the basic principles of the influence of salinity on the life of the major groups of aquatic organisms, species composition of ichthyofauna in waters immediately adjacent to the Azov-Black Sea basin, the ways of the reconstruction of the ichthyofauna that directly affect the productivity of these natural-born waters.

The information on the level and temperature conditions changes of the Neman river are presented in the article. Decrease of the water level during 1955–2007 is indicated and practically water is absent in the floodplain. At present the ice melt and the triggering temperature of fish spawning are beginning earlier. These changes have negatively affected conditions of fish reproduction.

Data of seasonal dynamic of fish invasion by ectoparasites in fish-farms of Belarus and influence of infusoria g. Chilodonella and monogenetic fluke g. Dactylogyrus on hematological characteristics of underyearling and two–year–old carp are presented.

Information about new preparation against ectoparasites of fish is given. Two preparations (Disol–K and Disol–Na) were developed on the base of native substances. They are effective for treatment against the most widespread and dangerous fish parasites (Trichodina sp., Ichthyophthirius multifiliis, Dactylogyrus sp. and etc.).

The species wealth of algae of fish ponds is shown. It is determined, that species from geniuses Microcystis, Anabaena и Aphanizamenon can amount to great values of biomass due to a short time. The necessity of more detailed study of species composition and taxonomic structure of phytoplankton of fish ponds and necessity of creation unified electronic date base are noted. The information about species composition of phytoplankton and presence of potential-dangerous toxic species could reduce to negative influence on aquaculture by such species.