|
|
Diversity and relative biovolume of benthic diatom assemblages in relation to environmental conditions.
Šoljaková, Tereza ; Kulichová, Jana (advisor) ; Chattová, Barbora (referee)
iv ABSTRACT Benthic diatoms are due to a number of positive characteristics (such as high abundances, diversified communities, sensitive responses to environmental conditions, capturing long-term changes in the environmental conditions) currently the most commonly used bioindicators of the ecological status of freshwater ecosystems. However, due to problems associated with the use of traditional methods based on species composition (time-consuming identification, presence of species complexes, and requirements for calibration of water quality indexes for geographical regions) searching for alternative methods has been induced. The monitoring of the size structure of diverse diatom communities has been proposed as one of the methods. This approach would mainly eliminate the necessity of time-consuming determination of species. The main purpose of this thesis was therefore to determine the relationship between the size structure of benthic diatom communities, expressed as the relative biovolume, and selected environmental factors (pH, conductivity, habitat type) within freshwater lentic habitats. Furthermore, the variability of biovolume in dependence on environmental variables was compared with the change in species composition. If there would be a similar response pattern of both the biovolume and species...
|
|
|
Diversity and relative biovolume of benthic diatom assemblages in relation to environmental conditions.
Šoljaková, Tereza ; Kulichová, Jana (advisor) ; Chattová, Barbora (referee)
iv ABSTRACT Benthic diatoms are due to a number of positive characteristics (such as high abundances, diversified communities, sensitive responses to environmental conditions, capturing long-term changes in the environmental conditions) currently the most commonly used bioindicators of the ecological status of freshwater ecosystems. However, due to problems associated with the use of traditional methods based on species composition (time-consuming identification, presence of species complexes, and requirements for calibration of water quality indexes for geographical regions) searching for alternative methods has been induced. The monitoring of the size structure of diverse diatom communities has been proposed as one of the methods. This approach would mainly eliminate the necessity of time-consuming determination of species. The main purpose of this thesis was therefore to determine the relationship between the size structure of benthic diatom communities, expressed as the relative biovolume, and selected environmental factors (pH, conductivity, habitat type) within freshwater lentic habitats. Furthermore, the variability of biovolume in dependence on environmental variables was compared with the change in species composition. If there would be a similar response pattern of both the biovolume and species...
|
|
|
Diversity of Cryptosporidium spp. infecting rodents from genus Apodemus in the Czech Republic
ČONDLOVÁ, Šárka
We investigated the species and genotypes of Cryptosporidium infecting wild rodents from the genus Apodemus in ten areas in the year 2012 in the Czech Republic. A total of 207 faecal samples, 182 samples of Apodemus flavicollis and 25 of Apodemus sylvaticus, were screened for presence of Cryptosporidium spp. using both the aniline-carbol-methyl violet staining method and molecular tools. Microscopy examination revealed the presence of Cryptosporidium spp. oocyst in 24 samples of Apodemus flavicollis and 1 sample of Apodemus sylvaticus. Genomic DNA was isolated from both microscopy positive and negative samples. Using the nested PCR amplifying gene encoding the small ribosomal subunit (SSU rRNA) 25 samples were detected positive for the presence of Cryptosporidium-specific DNA. The same results were obtained also in the nested PCR amplifying gene encoding actin. All microscopy positive samples were also PCR positive. Only 19 samples were successfully sequenced, following phylogeny analyses showed presence of two new genotypes. First genotype is phylogenetically related to Cryptosporidium ubiquitum (1 sample) and the second genotype (consisting of several subgroups) related to C. canis (18 samples). The new genotypes seem to be host specific, however this hypothesis needs to be verified using experimental infection in the future. This is the first report of these Cryptosporidium genotypes in Apodemus spp. and for the first time ever.
|
guest ::
