24 June 2012 ture or sale to customers in other Central European countries. Smaller hatcheries of local angling clubs produce larvae and juveniles of different game fish species, such as trout, grayling, burbot (Lota lota), and other riverine fish for stocking. Hatcheries are used for the final phase of fish reproduction, including temperature manipulation of broodstock before reproduction, hormonal treatment, stripping of eggs and sperm, egg fertilization, and incubation and hatching. Broodstock culture and management are performed under outdoor conditions in ponds and angling grounds. This production system uses pondcultured or wild broodstock that are spawned once per year during the natural spawning period. This means that hatcheries of Czech fish farms are used seasonally, without stimulation of out-of-season spawning. Czech hatcheries produce highquality fish gametes with high fertilization rates (85-100 percent) and high quality larvae with hatching rates from 65 to 90 percent. Hatcheries are distributed throughout the country and cover almost all the total requirement for fish larvae for stocking. Only a negligible part of the total requirement for fish larvae (mainly zander and European catfish) is obtained by semi-artificial methods of reproduction. Commercial Fish Species Common carp (Cyprinus carpio) is the most important fish species of Czech pond aquaculture and fisheries. Carp represents about 90 percent of commercial fish production and 70 percent of angling yield. Carp strains are based on two principal forms – scaly and mirror carps (Figure 13). The nutrition of younger fish is based preferably on zooplankton while older and bigger fish (>2 kg) are rather benthivorous. In ponds, common carp is the dominant species in polyculture. Another cyprinid, the tench (Tinca tinca, Figure 14) is cultured in much lower proportion because of food and habitat competition with common carp. However, the popularity of tench abroad makes its contribution to the domestic fish market rather marginal. European catfish is the largest Central European freshwater fish species. It can grow up to several tens of kilograms and trophy fish are around 100 kg. It is a predatory species characterized by white, tasty, slightly fatty flesh, which is highly desired by consumers. European catfish, together with some other predatory species (pike and zander), are important fish in pond polyculture. Besides the extra high quality of their flesh, these predatory species play a very important role in the control and regulation of the population size of less-valued small cyprinids (roach, Rutilus rutilus, bleak, Alburnus alburnus, bream, Abramis brama, and others) and percids (ruffe, Gymnocephalus cernua) in ponds. Silver carp and other herbivorous fish (i.e., Chinese carps: silver carp, bighead carp and grass carp) are cultured in pond polycultures because of their ability to ingest, use, and control plant organisms (Figure 14). While silver carp and bighead carp are filter feeders, consuming planktonic algae and small zooplankton (bighead), grass carp feeds on macrophytes, the growth of which can be easily controlled by appropriate proportion of grass carp in fish stocks. However, these three species are not native to Europe. Rainbow trout and brook trout are important species for Fig. 12. The production hatchery of Nové Hrady Ltd. fish farm near České Budějovice. (Photo by Tomáš Policar.) large companies and several small farms were formed from the original nearly 20 huge production enterprises. In 1991, a majority (21 entities) of large and medium-size farms, the national anglers unions, fish farming equipment producers, research institutes, fishery schools and some other fisheries institutions joined together to form the Czech Fish Farmers Association based in České Budějovice (South Bohemia). In the beginning of 2012, the Czech Fish Farmers Association had 71 members. Members of this association, which is also a member of the Federation of European Aquaculture Producers, manage nearly 90 percent of the pond area and produce about 90 percent of all the fish for market in the Czech Republic. The association also maintains close contact with about 40 farms that are not among its members. The industry has become highly concentrated over the past 10 years with seven companies controlling over 50 percent of national carp production. These companies employ approximately 1500 people throughout the Czech Republic. The main activities of the Czech Fish Farmers Association include the coordination of activities related to legislative standards (both Czech and European), state subsidy and fisheries funds, coordination of fish and waterfowl breeding, legislative and educational services for members, the analyses of damage caused by fish predators and its compensation, statistics of production and market outcome in fisheries, realization of joint marketing strategies, and management of trademarks. One other task is to maintain and strengthen the position of highly professional and prosperous Czech fish farmers, including environmental connections and out-of-production social functions of fish ponds. The Czech Fish Farmers Association represents and asserts the interests of its members as well as all of Czech fish farming in local agriculture and food bodies. Under the title Rybníkářství (Fish-Pond Farming), the association publishes its own periodical. Hatcheries Each medium or large Czech fish farm has a hatchery for larval production of commercial fish species (Figure 12). Fish larvae production is used for subsequent steps of pond fish cul-
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