|
|
The present distribution of species of the family Cobitidae over the Slovakian drainage area of the Tisza River
Koščo, J. ; Košuth, P. ; Lusková, Věra ; Lusk, Stanislav ; Košuthová, L. ; Halačka, Karel
Cobitis elongatoides is common to frequent in the eastern Slovakian part of the Tisza drainage area (d.a.) where it populates all habitat types. The occurrence of this species is less frequent in the western part of the Tisza d.a. No marked differences have been observed in the past and present distribution of this species. The occurrence of Misgurnus fossilis is concentrated in the lowland areas of the Tisza d.a., particularly in its eastern part. Ichthyocoenoses in which M. fossilis occurs are poorer in species, and they overlap considerably with those containing C. elongatoides but differ markedly from those containing Sabanejewia balcanica. M. fossilis was rather successful in adapting to artificial wetlands. The species is rather rare in western part of the Tisza d.a. The range of S. balcanica is shifted more upwards to the submontane region, exclusively in running waters. No marked differences have been observed in the past and present distribution of this species.
|
|
|
The Red List of lampreys and fishes in the Czech Republic - Version 2005
Lusk, Stanislav ; Hanel, L. ; Lusková, Věra ; Lojkásek, B. ; Hartvich, P.
The new Red List was compiled on the basis of data obtained in the course of five past years. Besides the overall evaluation for the Czech Republic, the data were separately evaluated for the North Sea, Baltic Sea, and Black Sea basins. The status and degree of danger imminent to the populations of the particular species were evaluated also separately for each of the 16 water regions. Compared to the 2000 evaluation, classification was changed for following species: Salmo salar (previously EW, now CE), Acipenser ruthenus (NE / CE), Sabanejewia balcanica (EX / CE), Zingel streber (EX / CE), Chondrostoma nasus (EN / VU), Lota lota (VU / NT), Rhodeus amarus (NT / EN), Leucaspius delineatus (NT / EN), Alburnoides bipunctatus (VU / EN), and Carassius carassius (VU / EN). The degree of jeopardy for Alburnoides bipunctatus, Vimba vimba, Rhodeus amarus, Carassius carassius, Misgurnus fossilis is basically different in different water regions, varying between Extinct and Near Threatened.
|
|
|
Biodiversity of fishes in the Czech Republic (VI)
bThis was already a sixth konference on fish biodiversity in the course of the past decade. The main topics of this conference included fish biodiversity on the specific and intraspecific level, risk factors, and ways to protect it. Twenty-five papers were presented to the conference.
|
|
|
Problems posed by the protection of lamprey and fish localities of European importance in the drainage areas of the Dyje, Morava, and Odra rivers
Lusk, Stanislav ; Lusková, Věra ; Lojkásek, B. ; Halačka, Karel
In consequence of the accepted legislation concerning the protection of lamprey and fish species of European importance, potential sites of community interest (pSCI) have been selected for such species. At present, the national list of the proposed pSCI is being examined by the European Commission. If approved upon, the pSCI will be proclaimed "special areas of conservation" within the NATURA 2000 system. Although such pSCI and their populations are protected by legislation, there occur risks that endanger, both directly and indirectly, the quality of the pSCI and the population of the particular species. The examples mentioned in the paper indicate that such risks include local emergency pollution, construction of weirs and small hydraulic power plants, extraction of sediments from streambeds, cruising vessels, and stream modification. Such risks are due to the inconsequence and reluctance in observing the legal protection measures by concrete authorities of nature conservation.
|
|
|
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.
|
|
|
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.
|
guest ::
