water reservoir Kružberk, bream, length growth, weight growth, fecundity

Práce je první studií kaprovitých ryb v nádrži Kružberk . Zabývá se růstem a plodností cejna velkého ve vodárenské nádrži Kružnerk. bylo zjištěno, že délkový růst do stáři tří let je pomalý a ve starším věku průměrný. Hmotnostní růst jsou ve srovnání s údaji z jiných podobných lokalit velmi rychlý. Plodnost odpovídá průměrnýým hodnotám zjištěným v jiných vodních nádržích.

The study results have been obtained by analysing the sample of 280 individuals of Abramis brama caught in the Kružberk reservoir in the years 2004 and 2005. The lengths of the caught fish ranged from 74 to 390 mm and their weight varied from 10 to 1510 g. The comparison of these data with data gained in other reservoirs in the Czech Republic suggests that the length growth of the bream in Kružberk, in the juvenile stage of up to three year-of-age, is slow, while it becomes above the average in later years. The found weight growth, when compared with the publicised data gained from other reservoirs in the Czech Republic, was extraordinarily fast. The fertility was studied with the sample of 27 females 6 - 9 years old. The found average value was 111 thousand roes. When compared with data from other localities, it was the average.