Number of found documents: 348
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Biomanipulační opatření na vodárenské nádrži Hamry - slabá odezva fytoplanktonu na redukci biomasy planktonofágních ryb
Jurajda, Pavel; Adámek, Zdeněk; Janáč, Michal; Roche, Kevin; Mikl, Libor; Rederer, L.; Zapletal, T.; Koza, V.; Špaček, J.
2014 - Czech
One measure commonly used for improving water quality in open waters is biomanipulation of fish stock. Previous studies in shallow lakes confirm the importance of reducing cyprinid populations for increasing zooplankton. Empirical results from reservoirs, however, are scarce. The aim of this study was to evaluate the effect of an intensive reduction of cyprinid fishes and perch fry density between 2009 and 2013 on water quality in the Hamry drinking water reservoir. The abundance of common bream broodstock decreased by around 12 000 individuals over the five years, and biomass dropped below 20 kg.ha-1. Stocking with pike and zander proved less effective. In reservoirs similar to Hamry, reduction of bream biomass can be a highly effective means of increasing filtering zooplankton biomass. Phytoplankton dynamics, however, appear to depend on additional factors, with nutrient loading (especially phosphorus) probably playing the primary role. Keywords: phytoplankton; Hamry water supply reservoir Available on request at various institutes of the ASCR
Biomanipulační opatření na vodárenské nádrži Hamry - slabá odezva fytoplanktonu na redukci biomasy planktonofágních ryb

One measure commonly used for improving water quality in open waters is biomanipulation of fish stock. Previous studies in shallow lakes confirm the importance of reducing cyprinid populations for ...

Jurajda, Pavel; Adámek, Zdeněk; Janáč, Michal; Roche, Kevin; Mikl, Libor; Rederer, L.; Zapletal, T.; Koza, V.; Špaček, J.
Ústav biologie obratlovců, 2014

Prostorová distribuce kaprů v polointenzivním rybníce
Mrkvová, Markéta; Zukal, Jan; Adámek, Zdeněk; Šútovský, I.; Jurajda, Pavel
2014 - Czech
In semi-intensive pond aquaculture, the dietary requirements of the species cultured (mainly carp Cyprinus carpio) are guaranteed through consumption of natural food organisms together with "supplementary" feed inputs. As a result, we hypothesise that carp will utilise the whole area of the pond in their search for those places where natural food is available. To date, there has been no in-depth study on fish behaviour and feeding habits in such ponds, despite the possibility of food competition where fish are stocked at high densities. Such competition could lead to decreased growth in younger fish cohorts, leading to poorer flesh quality. In this study, we use radio-telemetry to provide new information on carp behaviour in a 130ha pond under semi-intensive aquaculture. Our results indicate that fish distribution in the pond is uneven, with fish using approximately two-thirds of the pond area. This behaviour was partly influenced by size-class. Some fish tended to remain at localities where supplementary food was regularly provided, but some of them used both localities with supplementary and natural food. These results should prove useful for improving fish feeding regimes in ponds using a similar semiintensive system to our model pond. Available on request at various institutes of the ASCR
Prostorová distribuce kaprů v polointenzivním rybníce

In semi-intensive pond aquaculture, the dietary requirements of the species cultured (mainly carp Cyprinus carpio) are guaranteed through consumption of natural food organisms together with ...

Mrkvová, Markéta; Zukal, Jan; Adámek, Zdeněk; Šútovský, I.; Jurajda, Pavel
Ústav biologie obratlovců, 2014

Hlaváčovité ryby - potravní konkurenti našich původních druhů ryb?
Všetičková, Lucie; Jurajda, Pavel; Vašek, Mojmír; Adámek, Zdeněk; Roche, Kevin
2014 - Czech
To date, two species of the non-native Gobiidae family have been recorded in the Czech Republic: the tubenose goby (Proterorhinus semilunaris) and round goby (Neogobius melanostomus). The aim of this study was to assess the dietary habits of these two species, with the relationship between goby diet and that of native species (potential competition, predation) of particular interest. Early results suggest that the main dietary items of both gobiids are common benthic invertebrates such as Chironomidae, Trichoptera and Ephemeroptera. Fish eggs and fry were rarely taken by either species and, when taken, consisted almost exclusively of eggs and fry of their own species (cannibalism). In addition, the round goby was shown to be necrophagous, scavenging on large fish carcasses. This behaviour si relatively rare in the Czech fish assemblage. Our results suggest that tubenose and round goby, while not predating heavily on native benthivorous species, may still represent possible competitors. Keywords: tubenose goby; round goby; Czech Republic Available on request at various institutes of the ASCR
Hlaváčovité ryby - potravní konkurenti našich původních druhů ryb?

To date, two species of the non-native Gobiidae family have been recorded in the Czech Republic: the tubenose goby (Proterorhinus semilunaris) and round goby (Neogobius melanostomus). The aim of this ...

Všetičková, Lucie; Jurajda, Pavel; Vašek, Mojmír; Adámek, Zdeněk; Roche, Kevin
Ústav biologie obratlovců, 2014

Multilocus phylogeny of Sciurini tree squirrels
Pečnerová, P.; Martínková, Natália
2012 - English
Phylogenetic relationships inside the tribe Sciurini produce conflict between older morphological research and modern molecular studies. We provided a detailed phylogenetic analysis by incorporating eight loci and various methods of data processing. We used prevailing and user-friendly software packages (Geneious, BioEdit, MrBayes, ModelTest). Evolutionary history of Sciurini squirrels was examined by means of Bayesian inference of concatenated data set and six supertree construction methods. The concatenated data and supertrees generated by SuperTriplets, modified MinCut, standard MRP and veto supertree (without source tree correction) yielded similar results with taxa grouped according to their zoogeographic distribution. The genus Tamiasciurus formed a separate evolutionary lineage at the base of our trees and the other taxa gradually diverged into Palaearctic/Indomalayan, Nearctic and Neotropical groups. The other used methods, MinCut, Purvis-MRP and veto (with source tree correction) showed deviations from this pattern. Keywords: phylogeny; supermatrix; supertree; squirrels Available at various institutes of the ASCR
Multilocus phylogeny of Sciurini tree squirrels

Phylogenetic relationships inside the tribe Sciurini produce conflict between older morphological research and modern molecular studies. We provided a detailed phylogenetic analysis by incorporating ...

Pečnerová, P.; Martínková, Natália
Ústav biologie obratlovců, 2012

Reconstructing phylogeny from patchy data of rodents
Martínková, Natália; Moravec, J.
2012 - English
To reveal phylogeny of sparsely sequenced taxa, standard methods could not be successfully used due to patchy character of data and new methods had to be developed. We summarize such methods and present their funcionality on phylogeny of Arvicolini voles. Analyzing tree space with terraces, we have found that supermatrix approach is superior to supertree approach in extracting signal from data and determining a resolved and well-supported phylogeny. The most widely used program from Bayesian phylogeny inference fails to determine the correct lengths of branches in a large supermatrix with a lot of missing data, it still successfully determines the true tree topology. Keywords: phylogeny; supermatrix; supertree; arvicolini; Bayesian inference Available at various institutes of the ASCR
Reconstructing phylogeny from patchy data of rodents

To reveal phylogeny of sparsely sequenced taxa, standard methods could not be successfully used due to patchy character of data and new methods had to be developed. We summarize such methods and ...

Martínková, Natália; Moravec, J.
Ústav biologie obratlovců, 2012

Tree of life in a gappy genomic era
Martínková, Natália
2012 - English
Increasing volume of publicly available DNA sequence data enables comprehensive studies that address integrative questions. For these projects, bioinformatic analysis requires advanced methods and computational infrestructure. I present the character of DNA sequence matrices for multilocus datasets, which contain large portions of missing data. A condition critical for analysis of multilocus data is that datasets for all loci or genes need to have partially overlapping taxon sets. The work-flow for analysing such data differs between supermatrix and supertree estimation of species trees. In the supermatrix approach, aligned sequences for all genes are concatenated and the species tree is estimated directly from a partitioned matrix. In the supertree approach, gene sequence alignments are used for inference of gene trees. Those are then combined into a species supertree. Smaller projects could benefit from utilising all available information in the supermatrix. Larger projects should rely on supertree methods for computational optimisation. Keywords: DNA sequence evolution; phylogeny; multilocus genotyping; supermatrix; supertree Available at various institutes of the ASCR
Tree of life in a gappy genomic era

Increasing volume of publicly available DNA sequence data enables comprehensive studies that address integrative questions. For these projects, bioinformatic analysis requires advanced methods and ...

Martínková, Natália
Ústav biologie obratlovců, 2012

Genetic diversity in populations
Martínková, Natália; Zemanová, Barbora
2011 - English
Genetic diversity accumulates over time on the level of DNA sequence with accumulation of mutations. It is additionally increased with population admixture, and the decrease in genetic diversity is often the first indication of detrimental processes affecting populations, such as reduction in the number of breeding individuals or breeding of close relatives. Nucleotide diversity shows how different the sequences of a given gene are in a population. Gene diversity estimates how likely two individuals are to share the same sequence of a gene. Number of alleles is the count of different versions of a gene with differing sequences, and this is corrected for sample size in estimation of allelic richness. Heterozygosity is the average frequency that an individual will have two different copies of a gene. Keywords: nucleotide diversity; haplotype diversity; heterozygosity; Hardy-Weinberg equilibrium Available at various institutes of the ASCR
Genetic diversity in populations

Genetic diversity accumulates over time on the level of DNA sequence with accumulation of mutations. It is additionally increased with population admixture, and the decrease in genetic diversity is ...

Martínková, Natália; Zemanová, Barbora
Ústav biologie obratlovců, 2011

Ryby jako významný bioindikátor kvality vodního prostředí horních částí Tiché Orlice a Divoké Orlice
Lusk, Stanislav; Lusková, Věra; Korunová, Vlasta
2011 - Czech
Výzkumy na území regionu Orlice v průběhu posledních 20 let umožnily poznání druhové skladby rybích společenstev řek Tichá Orlice a Divoká Orlice. V tocích se nachází rybí společenstvo salmonidního typu s dominancí druhů Salmo trutta, Thymalus thymallus, Cottus gobio, Lampetra fluviatilis. Znečištění postupně se omezily vybudované čistírny odpadních vod a výrazné snížení intenzity zemědělské činnosti. Specifický problém představuje znečištění rtutí v oblasti Králík na horním části Tiché Orlice. Zdrojem kontaminace prostředí rtutí byla výroba zářivek v Králíkách, která byla ukončena v roce 1990. I když se kontaminace vody a následně i ryb rtutí v průběhu času snižuje, přesto hodnoty rtuti ve svalovině ryb přesahují hygienický limit (0,1 mg.kg-1). U rybářů konsumujících ryby ulovené v Tiché Orlici bylo zjištěno zvýšené množství rtuti ve vlasech. Prozatím nebylo přistoupeno k rehabilitaci upravených a regulovaných toků včetně drobných potoků v oblasti horní části Tiché Orlice. Investigations, implemented in the river network of the "Orlice" region over the past twenty years, made it possible to obtain data on the fish communities inhabiting the Tichá Orlice and Divoká Orlice rivers. The rivers are inhabited by salmonid fish communities dominated by Salmo trutta, Thymallus thymallus, Cottus gobio, and Lampetra fluviatilis. Water pollution was gradually limited by building water treatment plants as well as by the significant decrease in the intensity of agricultural activities. The environmental pollution with mercury in the Králíky region, lying on the upper reaches of the Tichá Orlice River, is a specific problem. Nevertheless, the mercury content in fish muscles has exceeded the hygienic limit (0.1 mg.kg-1). Fishermen consuming fish angled in the Tichá Orlice River have shown increased mercury contents in their hair. Keywords: fish; "Orlice" region Available at various institutes of the ASCR
Ryby jako významný bioindikátor kvality vodního prostředí horních částí Tiché Orlice a Divoké Orlice

Výzkumy na území regionu Orlice v průběhu posledních 20 let umožnily poznání druhové skladby rybích společenstev řek Tichá Orlice a Divoká Orlice. V tocích se nachází rybí společenstvo salmonidního ...

Lusk, Stanislav; Lusková, Věra; Korunová, Vlasta
Ústav biologie obratlovců, 2011

Rybí společenstvo jako indikátor degradace toku
Jurajda, Pavel; Janáč, Michal; Ondračková, Markéta; Adámek, Zdeněk; Valová, Zdenka; Streck, G.; Machala, M.; Wenger, M.; Segner, H.
2010 - Czech
V příkladové studii na Bílině se ryby na úrovni společenstva projevily jako dobrý a rychlý indikátor ekologického stavu toku, avšak pro indikaci chemických látek v řece je nutné hodnotit specifické parametry na úrovni jedince. Keywords: fish community; river degradation; Bílina River Available at various institutes of the ASCR
Rybí společenstvo jako indikátor degradace toku

V příkladové studii na Bílině se ryby na úrovni společenstva projevily jako dobrý a rychlý indikátor ekologického stavu toku, avšak pro indikaci chemických látek v řece je nutné hodnotit specifické ...

Jurajda, Pavel; Janáč, Michal; Ondračková, Markéta; Adámek, Zdeněk; Valová, Zdenka; Streck, G.; Machala, M.; Wenger, M.; Segner, H.
Ústav biologie obratlovců, 2010

Revitalizace toku Moravy versus podnikatelské záměry
Halačka, Karel; Mendel, Jan; Papoušek, Ivo; Vetešník, Lukáš
2009 - Czech
Tok řeky Moravy je významným nadnárodním biokoridorem s velkým biologickým potenciálem, o čemž svědčí i výsledky recentních ichtyologických sledování. Existuje plán revitalizačních projektů s cílem zprůchodnění migračních barier a repatriaci původních druhů živočichů. Současně se však na toto území soustřeďuje řada podnikatelských záměrů, jejichž realizace by tyto snahy zcela znemožnila či omezila. Měl by proto být nejprve proveden komplexní biologický průzkumu celého toku Moravy a následně vypracován detailní projekt zpřírodnění říční nivy včetně stále existujících fragmentů původního koryta. Ten by pak posloužil jako základ pro centrálně posuzované potenciální podnikatelské záměry. The course of the Morava River is an important supranational biocorridor with significant biological potential. This is attested also by results of recent ichthyological surveys. There is a plan of revitalization projects aimed at making migration barriers passable and also at repatriation of indigenous animal species. At the same time, there is a number of business plans focusing on the area, while their realization would severely restrain or even disallow the revitalization efforts. Therefore, a complex biological survey of the whole Morava River course should be performed first, and a detail project of naturalization of the floodplain, including the still existing fragments of original river channel, should be elaborated subsequently. Such project would then constitute a qualified basis for centrally assessed potential business plans. Keywords: Morava River; fish migration; repatriation; Gobio; Romanogobio Available at various institutes of the ASCR
Revitalizace toku Moravy versus podnikatelské záměry

Tok řeky Moravy je významným nadnárodním biokoridorem s velkým biologickým potenciálem, o čemž svědčí i výsledky recentních ichtyologických sledování. Existuje plán revitalizačních projektů s cílem ...

Halačka, Karel; Mendel, Jan; Papoušek, Ivo; Vetešník, Lukáš
Ústav biologie obratlovců, 2009

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