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Biomorphometry and growth rate of the sterlet (Acipenser ruthenus) in the Czech Republic
Prokeš, Miroslav ; Baruš, Vlastimil ; Peňáz, Milan ; Baránek, V. ; Ošanec, J. ; Šutovský, I.
Two samples of 40 and 30 juvenile specimens of the sterlet (Acipenser ruthenus Linnaeus, 1758) reared in special aquacultural facilities in the Czech Republic (and originating from Russia), and in the Slovak Republic (originating in the Danube Slovak section) were biometrically analysed and compared. Specimens did not differ in the maximum-minimum range of their meristic characters from the description presented for sterlet, but differ significantly in mean values in 4 (of 6) meristic and 14 (of 27) metric characters compared. On the basis of UPGMA it was found that the sample of sterlet from the CR, clusters well with other samples of the sterlet population. On the basis of PCA affinities of sterlet samples with hybrid samples of bester (A. ruthenus x Huso huso) were found. In comparative rearing of juvenile sterlet and Siberian sturgeon (Acipenser baerii) under identical experimental condition intensive growth rates in the Siberian sturgeon were found.
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Species determination of coregonid stocks
Prokeš, Miroslav ; Baruš, Vlastimil ; Peňáz, Milan ; Kubišta, O. ; Melichar, M. ; Špinar, M.
On the basis of results in reproduction biology, early ontogenesis and morphometrics of Coregonus maraena, C. peled and their reciprocal hybrids, the characterization of artificial reproduction development and morphometrical parameter changes in the parental species due to artificial hybridization is represented here from 1970 up to the present. On the example of populations of both aquacultured coregonid species, reared in the region of the Českomoravská vrchovina Highland, the determinative characterization of eggs, eleuterembryos and juvenile specimens are presented. To be the most important determinative characters, considered are: egg size, number of myotomes, size of hatching embryos, number of gill rackers, mouth position, body depth, number of rays and anal fin size. The actual population of C. maraena does not differ morphometrically from its state before 1970, the population of C. peled differs morphometrically from the state after introduction in 1970.
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Effects of fragmentation by impoundments and of pollution in the River Haná on species diversity on the fish community
Prokeš, Miroslav ; Baruš, Vlastimil
In the River Haná, 23 fish species belonging systematically to 6 families (Salmonidae, Thymallidae, Esocidae, Cyprinidae, Balitoridae, Percidae) were found. Due to river pollution in five localities, no fish occurrence was found, in the other 7 localities, the occurrence of individual species varied from 5 to 14 specimens. A natural recolonization of the poisened stream by fish occurred in two localities in the River Haná lower reaches long 8.4 km from the confluence with the River Morava.
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Phases of the ontogenesis of the Mušov Reservoir of the waterwork Nové Mlýny - fish yield and condition parameters of silver bream (Blicca bjoerkna)
Baruš, Vlastimil ; Peňáz, Milan ; Prokeš, Miroslav
Overall yields of the carp and of the non-preferred group of coarse "other fish" exhibited in the Mušovská nádrž Reservoir (Fishing ground MRS Dyje 7) significant changes during 1981-2001. The decrease of yield during 1996-1999 is significantly correlated with a decreased fishing pressure (number of fishing visits per year and hectare of fishing ground) while it insignificantly correlates with the quantity of annually stocked carps. The length/weight relationship of the silver bream, if comparing the values from 1980 with those from 1996, exhibit a significant drop. It was concluded, that the reservoir is actually in a phase of stabilised production and characteristic by a feeding competition between the carp as a preffered game fish and the coarse fishes. Also an increased predation by wells exhibited on the non-predatory fishes including the stocked carp can not be excluded.
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Fish assemblage and stone loach (Barbatula barbatula) population in the river Haná
Prokeš, Miroslav ; Baruš, Vlastimil ; Peňáz, Milan ; Koubková, B. ; Gelnar, M.
Ecological parameters of the fish assemblage and stone loach population are presented. In total, 25 fish species from 7 families in the river Haná (23 species), including its sources Velká Haná (5 species) and Malá Haná (7 species), were found. Index of species diversity (H') ranged from 0.00 to 1.96, abundance was 89.0 - 22754.8 (mean = 3874.5) exx.ha-1 and biomass was 1.87 - 599.1 (mean = 115.07) kg.ha-1. In five localities in middle and lower parts of the Haná of total 20 localities, no fish was found. Stone loach occured in the whole longitudinal profile within the trout and cyprinid assemblages in abundance of 12.7 - 18260.7 (mean = 2452.8) exx.ha-1 and in biomass of 0.04 - 58.8 (mean = 10.27) kg.ha-1. Species weight dominance (D) was 0.31 - 15.00% (mean = 4.96%). Population of stone loach is a suitable in the stream for investigations of the fish metazoan parasite biology and ecology.
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Heavy metals in parasite-host systems: tapeworm vs. fish
Baruš, Vlastimil ; Tenora, F. ; Prokeš, Miroslav ; Peňáz, Milan
Concentrations of heavy metals in two parasite-host systems (tapeworm vs. fish) were analysed. In the system Ligula intestinalis vs. common bream Abramis brama, white bream Blicca bjoerkna and roach Rutilus rutilus were found in the biomass of plerocercoids mean heavy metal concentrations ranging in Pb 3.20-4.51, in Cd 0.21-0.31, in Cr 1.13-3.16 mg/kg in the 100% dry matter. Regarding the values of accumulation ratio, the parasite accumulated 12.5-18.9 time more Pb, 2.3-3.0 times more Cd, and 4.4-14.1 times more Cr, compared to heavy metal concentrations in the muscles of intermediate hosts.
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Fish species diversity in tributaries of the Haná stream
Prokeš, Miroslav ; Baruš, Vlastimil ; Peňáz, Milan ; Koubková, B. ; Gelnar, M.
Fundamental ecological parameters of the fish assemblages in the Brodecký potok (BP) and Rostěnický potok (RP) were presented. In th BP, 18 fish species, in the RP 11 fish species and in the whole river system of the Haná 30 fish species were presented. Index of species diversity (H') in the BP ranged from 0.3358 to 1.7161, abundance was 14359-66818 exx.ha-1 and biomass was 51.6-576.6 kg.ha-1. Stone loach occurred in the localities, where predator species (Esox lucius, Sander lucioperca and Perca fluviatilis) absented, in dominance 3.72-94.06% and biomass 18.84-53.1 kg.ha-1. Index of fish species diversity in the RP ranged from 0.7496 to 1.7268 abundance was 4490-14578 exx.ha-1 and biomass was 72.1-961.1 kg.ha-1. Stone loach occurred only in the stream mouth of BP in the dominance 3.79% and biomass 3.9 kg.ha-1.
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