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Nadezhda N. Degermendzhy - One of the best experts on this subject based on the ideXlab platform.
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Lake Shira, a Siberian salt lake: ecosystem structure and function. 1. Major physico-chemical and biological features
International Journal of Salt Lake Research, 1999Co-Authors: Tatyana A. Zotina, Alexander P. Tolomeyev, Nadezhda N. DegermendzhyAbstract:The specific composition, vertical distribution and daily migration of plankton in a meromictic salt lake, Lake Shira, have been investigated. The main structural components of the ecosystem are bacteria, algae and crustaceans. Since the late 1970s, blue-green algae are reported as dominant. Nowadays the phytoplankton is dominated by Lyngbya contorta, Microcystis ichtyoblabe (Cyanophyta), Cyclotella tuberculata (Bacillariophyta) and Dictyosphaerium tetrachotomum (Chlorophyta). The Zooplankton of Lake Shira comprises Arctodiaptomus salinus (Copepoda), Brachionus plicatilis and Hexarthra oxiuris (Rotatoria). Investigation revealed a stratified vertical distribution of all dominant species except Cyclotella with a maximum at a depth of 12--15 m during the summer growth period. Zooplanktons differ in the pattern of distribution and daily migration, but most Zooplankton tend to concentrate near the surface. The possible reasons for the vertical distribution of the plankton are discussed.
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Lake Shira, a Siberian salt lake: ecosystem structure and function
International Journal of Salt Lake Research, 1999Co-Authors: Tatyana A. Zotina, Alexander P. Tolomeyev, Nadezhda N. DegermendzhyAbstract:The specific composition, vertical distribution and daily migration of plankton in a meromictic salt lake, Lake Shira, have been investigated. The main structural components of the ecosystem are bacteria, algae and crustaceans. Since the late 1970s, blue-green algae are reported as dominant. Nowadays the phytoplankton is dominated by Lyngbya contorta, Microcystis ichtyoblabe (Cyanophyta), Cyclotella tuberculata (Bacillariophyta) and Dictyosphaerium tetrachotomum (Chlorophyta). The Zooplankton of Lake Shira comprises Arctodiaptomus salinus (Copepoda), Brachionus plicatilis and Hexarthra oxiuris (Rotatoria). Investigation revealed a stratified vertical distribution of all dominant species except Cyclotella with a maximum at a depth of 12–15 m during the summer growth period. Zooplanktons differ in the pattern of distribution and daily migration, but most Zooplankton tend to concentrate near the surface. The possible reasons for the vertical distribution of the plankton are discussed.
Tatyana A. Zotina - One of the best experts on this subject based on the ideXlab platform.
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Lake Shira, a Siberian salt lake: ecosystem structure and function. 1. Major physico-chemical and biological features
International Journal of Salt Lake Research, 1999Co-Authors: Tatyana A. Zotina, Alexander P. Tolomeyev, Nadezhda N. DegermendzhyAbstract:The specific composition, vertical distribution and daily migration of plankton in a meromictic salt lake, Lake Shira, have been investigated. The main structural components of the ecosystem are bacteria, algae and crustaceans. Since the late 1970s, blue-green algae are reported as dominant. Nowadays the phytoplankton is dominated by Lyngbya contorta, Microcystis ichtyoblabe (Cyanophyta), Cyclotella tuberculata (Bacillariophyta) and Dictyosphaerium tetrachotomum (Chlorophyta). The Zooplankton of Lake Shira comprises Arctodiaptomus salinus (Copepoda), Brachionus plicatilis and Hexarthra oxiuris (Rotatoria). Investigation revealed a stratified vertical distribution of all dominant species except Cyclotella with a maximum at a depth of 12--15 m during the summer growth period. Zooplanktons differ in the pattern of distribution and daily migration, but most Zooplankton tend to concentrate near the surface. The possible reasons for the vertical distribution of the plankton are discussed.
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Lake Shira, a Siberian salt lake: ecosystem structure and function
International Journal of Salt Lake Research, 1999Co-Authors: Tatyana A. Zotina, Alexander P. Tolomeyev, Nadezhda N. DegermendzhyAbstract:The specific composition, vertical distribution and daily migration of plankton in a meromictic salt lake, Lake Shira, have been investigated. The main structural components of the ecosystem are bacteria, algae and crustaceans. Since the late 1970s, blue-green algae are reported as dominant. Nowadays the phytoplankton is dominated by Lyngbya contorta, Microcystis ichtyoblabe (Cyanophyta), Cyclotella tuberculata (Bacillariophyta) and Dictyosphaerium tetrachotomum (Chlorophyta). The Zooplankton of Lake Shira comprises Arctodiaptomus salinus (Copepoda), Brachionus plicatilis and Hexarthra oxiuris (Rotatoria). Investigation revealed a stratified vertical distribution of all dominant species except Cyclotella with a maximum at a depth of 12–15 m during the summer growth period. Zooplanktons differ in the pattern of distribution and daily migration, but most Zooplankton tend to concentrate near the surface. The possible reasons for the vertical distribution of the plankton are discussed.
Alexander P. Tolomeyev - One of the best experts on this subject based on the ideXlab platform.
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Lake Shira, a Siberian salt lake: ecosystem structure and function. 1. Major physico-chemical and biological features
International Journal of Salt Lake Research, 1999Co-Authors: Tatyana A. Zotina, Alexander P. Tolomeyev, Nadezhda N. DegermendzhyAbstract:The specific composition, vertical distribution and daily migration of plankton in a meromictic salt lake, Lake Shira, have been investigated. The main structural components of the ecosystem are bacteria, algae and crustaceans. Since the late 1970s, blue-green algae are reported as dominant. Nowadays the phytoplankton is dominated by Lyngbya contorta, Microcystis ichtyoblabe (Cyanophyta), Cyclotella tuberculata (Bacillariophyta) and Dictyosphaerium tetrachotomum (Chlorophyta). The Zooplankton of Lake Shira comprises Arctodiaptomus salinus (Copepoda), Brachionus plicatilis and Hexarthra oxiuris (Rotatoria). Investigation revealed a stratified vertical distribution of all dominant species except Cyclotella with a maximum at a depth of 12--15 m during the summer growth period. Zooplanktons differ in the pattern of distribution and daily migration, but most Zooplankton tend to concentrate near the surface. The possible reasons for the vertical distribution of the plankton are discussed.
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Lake Shira, a Siberian salt lake: ecosystem structure and function
International Journal of Salt Lake Research, 1999Co-Authors: Tatyana A. Zotina, Alexander P. Tolomeyev, Nadezhda N. DegermendzhyAbstract:The specific composition, vertical distribution and daily migration of plankton in a meromictic salt lake, Lake Shira, have been investigated. The main structural components of the ecosystem are bacteria, algae and crustaceans. Since the late 1970s, blue-green algae are reported as dominant. Nowadays the phytoplankton is dominated by Lyngbya contorta, Microcystis ichtyoblabe (Cyanophyta), Cyclotella tuberculata (Bacillariophyta) and Dictyosphaerium tetrachotomum (Chlorophyta). The Zooplankton of Lake Shira comprises Arctodiaptomus salinus (Copepoda), Brachionus plicatilis and Hexarthra oxiuris (Rotatoria). Investigation revealed a stratified vertical distribution of all dominant species except Cyclotella with a maximum at a depth of 12–15 m during the summer growth period. Zooplanktons differ in the pattern of distribution and daily migration, but most Zooplankton tend to concentrate near the surface. The possible reasons for the vertical distribution of the plankton are discussed.
C. H. Fernando - One of the best experts on this subject based on the ideXlab platform.
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The Freshwater Zooplankton of Sri Lanka, with a Discussion of Tropical Freshwater Zooplankton Composition
International Review of Hydrobiology, 2007Co-Authors: C. H. FernandoAbstract:Based on the study of over 500 Zooplankton samples collected in Sri Lanka (Ceylon) during 1965–1974, the species composition from different habitats is analysed. The Zooplankton assemblage is typically tropical with relatively few species of Cladocera and Copepoda. The Rotifera include a large number of species of the genus Brachionus. The limnetic Zooplankton resembles the pond Zooplankton closely in that all the eurytopic species found in the different types of habitats, including ponds, also occur in the limnetic Zooplankton. The large Cladocera belonging to the genus Daphnia are very rare. In general, large zooplankters are absent. The size composition of the Zooplankton has a smaller range than in temperate regions. This is due to the absence of large-sized Zooplankton species. The reasons for the differences in species variety and size composition between Zooplankton of temperate and tropical regions is perhaps due to a number of factors. These include the effects of high and uniform temperatures, food availability and predation by fish and invertebrates.
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Seasonality and abundance of some dominant crustacean Zooplankton in Lake Awasa, a tropical rift valley lake in Ethiopia
Hydrobiologia, 1991Co-Authors: Seyoum Mengestou, C. H. FernandoAbstract:The Zooplankton of a Rift Valley lake in Ethiopia, Awasa, was sampled at 3 stations for 2 years (1986 and 1987) concurrently with various meteorological and limnological measurements. The spatial and temporal variation in abundance of some numerically dominant crustaceans, Mesocyclops aequatorialis similis (Copepoda), Thermocyclops consimilis (Copepoda) and Diaphanosoma excisum (Cladocera) is discussed. Temporal (months, sampling dates) rather than spatial (station) variability accounts for more than 50% of the total variance in Zooplankton abundance but horizontal patchiness exists during periods of high Zooplankton density. Sampling errors were generally low, except for counts of cyclopoid nauplii (subsampling) and Diaphanosoma (inter-replicate variance). Zooplankton showed distinct seasonality associated with the mixing cycle of the lake. Total numbers increased to more than 200 000 m^−3 during the unstratified period (July to September). Low numbers were evident during stratification (February to May) when Zooplankton numbers did not exceed 15 000 m^−3. Individual Zooplankton species and age classes showed variable seasonal amplitudes, ranging from 6.4 (nauplius 3) to 44.8 (copepodite 3 of Mesocyclops ). We discuss some possible causes for Zooplankton seasonality in Lake Awasa, and also review Zooplankton seasonal cycles in other tropical lakes, especially African ones.
Stanley I Dodson - One of the best experts on this subject based on the ideXlab platform.
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intraspecific variation in a predator affects community structure and cascading trophic interactions
Ecology, 2008Co-Authors: David M Post, Erika G Schielke, Eric P. Palkovacs, Stanley I DodsonAbstract:Intraspecific phenotypic variation in ecologically important traits is widespread and important for evolutionary processes, but its effects on community and ecosystem processes are poorly understood. We use life history differences among populations of alewives, Alosa pseudoharengus, to test the effects of intraspecific phenotypic variation in a predator on pelagic Zooplankton community structure and the strength of cascading trophic interactions. We focus on the effects of differences in (1) the duration of residence in fresh water (either seasonal or year-round) and (2) differences in foraging morphology, both of which may strongly influence interactions between alewives and their prey. We measured Zooplankton community structure, algal biomass, and spring total phosphorus in lakes that contained landlocked, anadromous, or no alewives. Both the duration of residence and the intraspecific variation in foraging morphology strongly influenced Zooplankton community structure. Lakes with landlocked alewives had small-bodied Zooplankton year-round, and lakes with no alewives had large-bodied Zooplankton year-round. In contrast, Zooplankton communities in lakes with anadromous alewives cycled between large-bodied Zooplankton in the winter and spring and small-bodied Zooplankton in the summer. In summer, differences in feeding morphology of alewives caused Zooplankton biomass to be lower and body size to be smaller in lakes with anadromous alewives than in lakes with landlocked alewives. Furthermore, intraspecific variation altered the strength of the trophic cascade caused by alewives. Our results demonstrate that intraspecific phenotypic variation of predators can regulate community structure and ecosystem processes by modifying the form and strength of complex trophic interactions.
