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Converting of juvenile zander (Sander lucioperca) to artificial diet (preliminary results)
Baránek, V. ; Mareš, J. ; Prokeš, Miroslav ; Jirásek, J. ; Spurný, P.
Weaning success of pond-reared zander (Zander lucioperca) fry was evaluated using three different converting methods: direct converting to dry feed (Bio-Optimal Start 0.5-0.8 mm) – variant A, three– day application of semi-moist feeding mixture on the base of fish – variant B and three-day application of semi-moist mixture + three-day co-feeding of semi-moist mixture and dry feed. These methods were evaluated regarding specific growth rate (SGR), Fulton´s factor of weight condition (FWC), survival and cannibalism. The average onset total length of fish was 35.22 ± 2.15 mm and the average individual weight was 0.31 ± 0.05 g. There were 600 individuals in each circular tank. The initial stock density was 0.62 g.l-1 (2 fish.l-1). The water temperature during this experiment fluctuated in intervals 22 – 24oC. Fish survival during a 14-day period of rearing ranged from 34.33% [C] to 50.33% [A]. Variant A and B were achieved better weaning performance than variant C regarding all parameters.
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Occurrence and characteristics of ide (Leuciscus idus Linnaeus, 1758) catches in drainage area of the Morava River
Prokeš, Miroslav ; Baruš, Vlastimil ; Peňáz, Milan
The ide, Leuciscus idus belongs to autochthonous, less numerous and endangered (vulnerable) fish species of the Czech Republic. In 2004, the fishing on ide was conducted on 51 non-salmonid (NS) fishing-grounds of the Moravian Anglers Union (MAU) on water area of 4622.4 ha. In total, 432 ides (= 0.31 ind.ha-1; 0.25 % of all captured fish) and 332 kg of ide biomass (= 0.23 kg.ha-1, = 0.10 % of total mass of captured fish) were captured in 2004. Mean individual mass of ide was 0.78 kg. In the period 1990-2004, 0.11 ind.ha-1 (= 0.067 % of all captured fish) and 0.075 kg.ha-1 (= 0.035 % of total mass of captured fish) in the NS fish-grounds of MAU were captured yearly. During 1953-1978, 1.67 ind.ha-1 and 1.41 kg.ha-1 of the ide were captured yearly in the riverine fishing-ground Dyje 7. General trend of catches is decreasing. Legislative species protection, artificial reproduction and restocking of fish fry and 1+ juveniles were realized.
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Invasive fish species in the Czech Republic
Lusk, Stanislav ; Lusková, Věra
In the Czech Republic, the following fish species are evaluated as invasive: Carassius auratus, a species showing a significantly negative influence on the occurrence of native species Carassius carassius and Tinca tinca in natural habitats. Certain manifestations and properties (such as the invasive way of dispersal, numerous populations, great ecological tolerance etc.) typical of invasive species can also be seen in Pseudorasbora parva, Ameiurus nebulosus, and Proterorhinus marmoratus. In some of its manifestations, even Cteropharyngodon idella can affect biodiversity in a negative way. One cannot exclude the future invasion or introduction of any alien species evaluated as invasive, particularly those of the genus Neogobius that occur in the Slovakian part of the Danube, and Perccottus glenii that has already invaded the Tisza River drainage area and the lower part of the Danube.
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Intraspecific diversity in the ichthyofauna of the Czech Republic, its knowledge and protection
Lusk, Stanislav ; Lusková, Věra
At present, 48 fish and 2 lamprey species occur in the waters of the Czech Republic. Of these, 22 fish species are protected by law all over the country or locally, the protection of 3 fish and 2 lamprey species is conditional. For the time being, there are no legal means to protect their intraspecific (genetic) diversity. In this point, one can only utilise certain indirect measures that follow from the limits pertaining to endangered species. The available knowledge of intraspecific diversity of the fish fauna in the Czech republic is fragmentary an incoherent. That is one of the causes of the absence of legislative means to protect the intraspecific diversity. In addition, the apprehension of this phenomenon by the piscatorial public is insufficient although this diversity is the most endangered by the very fishery management. Increased research and knowledge of the intraspecific diversity of particular species is inevitable as the basis for its conservation.
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Genus Cyprinus Linnaeus, 1758 - actual review on species diversity
Baruš, Vlastimil ; Peňáz, Milan ; Prokeš, Miroslav
In the genus carp (Cyprinus) is included currently 22 taxons in species levels and his fission into two subgenus: Cyprinus s. str. (with 17 species) and Mesocyprinus (with 5 species). Typical taxon on first subgenus Cyprinus (C.) carpio evaluate as a polytypical (with 4 subspecies). From 17 species of subgenus Cyprinus are 8 endemics only in Chinese province Yunnan (=Jünan), 1 species (C. qionghaiensis) province Sechwan, 1 species (C. acutidorsalis) on island Hainan, 5 species in northern as far as middle Vietnam and 1 species (C. intha) in Burma. Geographical distribution of 4 subspecies (C. carpio) is conformable with former views (Kirpichnikov 1967) and number of 2 - 3 domestication centres (Baruš et al. 2002). In subgenus Mesocyprinus registered species are Chinese faunistic elements with C. multitaeniata, that the was ascertained also in northern Vietnam.
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The natural seasonal changes in the food choice and digestive tract of wild ruminants
Kamler, Jiří ; Homolka, Miloslav
Herbivore populations all over Europe have been strongly influenced by human activities. A combination of harvest, changes in forest structure, supplementary feeding, predator extirpation and others factors have led in most cases to increases of their populations and a severe impact on the composition and structure of the forest vegetation. The food choice of free living ungulate species is strongly influenced by season and animal species and changes in diet composition and quality cause the changes in the digestive tract. Effective management of ungulate populations and forest ecosystems should be based not only on detailed information about the impact of deer browsing and the number of deer to harvest but also on the density of deer species, the food supply, the structure of diets consumed by individual species, attraction and quality of the individual components of food supply the total quality of food taken and seasonal changes in digestive tract.
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