Тaxonomic diversity of phytoplankton of fish ponds of Lviv Region

he article presents the results of research on the taxonomic diversity and ecological characteristics of phytoplankton in fish ponds of Lviv region. It was found that the phytoplankton of the studied water bodies was characterized by high taxonomic diversity and was represented by 170 species and intraspecific taxa belonging to 95 genera, 52 families, 29 orders, 13 classes and 7 systematic divisions. The dominant group of the floristic composition were Chlorophyta (49 – 64% of the total number of revealed species), the subdominants were Bacillariophyta (11 – 15%), Euglenozoa 7 – 20%) and Cyanobacteria 5 – 12%). Coefficients of species similarity according to Serensen (Ks = 0.620.83) and Kendel's rank correlation for leading families (τ = 0.540.73) and genera (τ = 0.410.70) were high that indicates the similarity of the species composition of algal communities of different farms. The analysis of the ecological characteristics of algae showed that planktonic 33 – 38%) forms predominated in phytoplankton in terms of biotope distribution. Plankton-benthic, epiphytic forms were of secondary importance, accounting for 26 – 29%) and 20 – 29%) of the total number of species with a known biotope distribution, respectively. Slow-flowing forms dominated in terms of rheophilicity 79 – 88%), in terms of salinity 82 – 91%) and relation to pH 73 – 86%)  indifferent species. The main share of phytoplankton saprobic indicator species was formed by β-mesosaprobes 51 – 59%) and o-α-mesosaprobes 17 – 19%), which characterize these water bodies as those with a moderate level of organic pollution.