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Fishes in streams of the Beskydy Protected landscape region
Lusk, Stanislav ; Lusková, Věra ; Halačka, Karel ; Lojkásek, B.
The river network of the Beskydy PLR (1,620 km2 ) belongs to the hydrological systems of Baltic and Black seas. It mainly consists of minor streams of the orders I and II. The basic components of their fish stock include Salmo trutta m. fario and Cottus poecilopus.In lower part of bigger streams are also additional species (Thymallus thymallus, Leuciscus cephalus, Alburnoides bipunctatus, Gobio gobio, Cottus gobio, etc.).
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Fish fauna of artificial wetland within the Chomoutovské jezero nature reserve, PLA Litovelské Pomoraví
Horák, Václav ; Lusk, Stanislav ; Lusková, Věra ; Halačka, Karel ; Mendel, Jan
The Chomoutov wetland was inhabited naturaly during extreme flood in 1997. During the research period, 2001-2003, 15 fish species were found in total. Most numerous within the fish community were populations of the species Rutilus rutilus, Scardinius erythropthalmus, Carassius auratus and Perca fluviatilis.
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Diploid, triploid and tetraploid silver crucian carp Carassius auratus from the lower reach of Dyje River: the first results of reproductive characteristics and experimental hybridization
Flajšhans, Martin ; Lusková, Věra ; Vetešník, Lukáš ; Halačka, Karel ; Rodina, Marek ; Lusk, Stanislav ; Gela, David
Diploid, triploid and tetraploid males of silver crucian carp, Carassius auratus, produced live motile spermatozoa, capable of fertilization. Flow cytometry for the relative DNA content in male gametes revealed spermatozoa of diploid males to be haploid, those of triploid males to be aneuploid and those of tetraploid male to be aneuploid and/or diploid. Concentration of spermatozoa and the percentage of live spermatozoa showed a tendency to drop with increasing ploidy level and this effect was significant for the tetraploid male compared to those of lower ploidy levels.
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Some biological characteristics of the invasion species Perccottus glenii
Halačka, Karel ; Vetešník, Lukáš ; Koščo, J.
The occurrence of this exotic species was first observed in the Latorica River, E Slovakia, in 1998. Perccottus glenii occupied the rivers Latorica, Bodrog and Tisza together with the aquatic habitats in their floodplains. We carried out analysis of growth, haematology, fecundity, morphology of skin and gonad of individuals Amur sleeper in the locality at Svata Maria (the Bodrog River drainage area). In the locality under study the invasion of Perccottus glenii resulted in an almost total destruction of numerous populations of the native species Umbra krameri, Carassius carassius, and Leucaspius delineatus. In the past, these species were among the most numerous in that locality. Perccottus glenii has appeared to be a typical 'invasive' species that is a serious threat for native fish species showing identical habitat requirements.
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The ploidy of Carassius auratus in the Czech Republic in light of the artificial reproduction
Halačka, Karel ; Vetešník, Lukáš ; Flajšhans, M.
State of population of Carassius "gibelio" (the sex ratio and ploidy level) was for a long time observed in the Dyje river floodplain, where it has expanded by natural migration from the Danube river through Morava river in 1975-1976. Results show the time dynamics for both parameters, with increasing proportion of males and increasing proportion of diploids of both sex and the formation diploid-polyploid complex. Diploid, triploid and tetraploid males and females of silver crucian carp, Carassius auratus, as well as males of silver Blicca bjoerkna and Rutilus rutilus, were used in mating. The results show different reaction of females on used sperm even in the same group of ploidy. The existence of some groups of the individuals with a different strategy of reproduction in frame single population could be the explanation.
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The influence of ploidy on the complete blood count in silver crucian carp
Vetešník, Lukáš ; Halačka, Karel ; Lusková, Věra ; Lusk, Stanislav
In the sample of 27 specimens of silver crucian carp (Carassius auratus) of different ploidy (5 diploids, 21 triploids and 1 tetraploid), the red component of complete blood count was found. Using the analysis of variance test, highly significantly lower erythrocyte count, insignificantly lower haemoglobin count and haematocrit value were proved. The mean corpuscular volume was increasing significantly with the ploidy increased, and mean corpuscular haemoglobin was increasing highly significantly with the ploidy increased.The tetraploid specimen indicated similar trend depending on the higher ploidy level.
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