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Foraging strategies of invertebrate predators in mountain lakes
Hrdličková, Jana ; Sacherová, Veronika (advisor) ; Hořická, Zuzana (referee)
In mountain lakes, which were affected by acidification in the past or in the present, invertebrate species have become top predators and they influence the whole community. This thesis deals with foraging strategies of three of these predators, Cyclops abyssorum and Heterocope saliens (Crustacea: Copepoda) and Glaenocorisa propinqua (Insecta: Heteroptera) in the model localities Černé lake, Plešné lake and Prášilské lake. The main aim was the determination of food composition and food preferences of these predators. The quality and quantity of consumed food I investigated with a microscope using a method which has not been published yet. To make a microscope preparation I used Potassium hydroxide or Lactic acid in order to dissolve soft organic matter, so that the chitinous particles were well visible. The found food of animal origin was subsequently compared with the prey availability with the use of Jacobs' index. In addition to this research, a feeding experiment with G. propinqua was carried out. The food of all the invertebrate predators was dependent on food availability or eventually on the season of the year. G. propinqua mostly preferred as a prey members of Daphniidae family and then the species Polyphemus pediculus (Cladocera), if they were available (Prášilské lake). In Plešné lake,...
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Foraging strategies of invertebrate predators in mountain lakes
Hrdličková, Jana ; Sacherová, Veronika (advisor) ; Hořická, Zuzana (referee)
In mountain lakes, which were affected by acidification in the past or in the present, invertebrate species have become top predators and they influence the whole community. This thesis deals with foraging strategies of three of these predators, Cyclops abyssorum and Heterocope saliens (Crustacea: Copepoda) and Glaenocorisa propinqua (Insecta: Heteroptera) in the model localities Černé lake, Plešné lake and Prášilské lake. The main aim was the determination of food composition and food preferences of these predators. The quality and quantity of consumed food I investigated with a microscope using a method which has not been published yet. To make a microscope preparation I used Potassium hydroxide or Lactic acid in order to dissolve soft organic matter, so that the chitinous particles were well visible. The found food of animal origin was subsequently compared with the prey availability with the use of Jacobs' index. In addition to this research, a feeding experiment with G. propinqua was carried out. The food of all the invertebrate predators was dependent on food availability or eventually on the season of the year. G. propinqua mostly preferred as a prey members of Daphniidae family and then the species Polyphemus pediculus (Cladocera), if they were available (Prášilské lake). In Plešné lake,...
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Diversity of fishpond zooplankton in Javořice highlands region
IŠTOK, Tomáš
It studied the species composition of pond zooplankton selected pond in Javořická highlands, near Nová Bystřice and Slavonice. Sampling was pelagial and at selected locations and littoral ponds. When selecting sites sampled, the emphasis was on the selection of sites with historical, expected or actual occurrence Heterocope saliens that occurs on sites with ponds and bogs around the aquatic environment with lower pH. These sites are usually extensively farmed. Found 69 species (24 Cladocera, 15 Copepoda, 30 Rotatoria). Confirmed the hypothesis that the greatest variety of species of zooplankton found at mesotrophic sites with moderate fisheries management.
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