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Status of the flatworm Crenobia alpina in the food network of a spring
Reslová, Marie ; Simon, Ondřej (advisor) ; Černý, Martin (referee)
This work focuses on food preferences of freshwater triclad Crenobia alpina and its position in spring food web. It explores the ability of C. alpina to capture living prey, considers ability of C. alpina and to survive feeding on several types of food. Furthermore it gives view on its occurence and ecological preferences in context of other spring species. One chapter is concerned with taxonomy, anatomy and ecology of Tricladida and C. alpina itself. Short term food-preference experiments show the ability of C. alpina to capture living Lumriculidae and larvae of Ephemeroptera. We don't confirm feeding of C. alpina on living Gammarus, although their occurence in our springs and ecological preferences are similar. C. alpina feeds significantly more on damaged prey without substantial afinity to any species. A year-long experiment on C. alpina in lab conditions finds that this flatworm is able to survive and even breed with nothing but filtred water. This fact connected with the observation of huge densities of flatworms in spring source, opens up a question whether C. alpina can be considered a real predator. Key words: Crenobia alpina, triclad flatworms, food preferences, spring
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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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Stable isotopes and the study of insects ecology
Javůrková, Jaroslava ; Šípek, Petr (advisor) ; Harant, Karel (referee)
Animal foraging ecology is an important part in the puzzle ecosystem relationships. This bachelor thesis presents review in the field of food ecology, especially insects. It focuses on the method of analysis of stable isotopes, which is one of the current and in recent decades a modern approach for studying this issue. Stable isotope analysis is compared with other frequently used methods for animal food ecology. The aim of this work is to introduce this method and its possible use in the study of insect food ecology. The first part provides the necessary theoretical background, practical application in laboratory and then it deals with the problems typically adressed by this method. Key words: stable isotopes, stable isotopes analysis, food ecology, food preferences, insects
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Use of Slugs in the Elementary and High School Teaching
Šrámková, Jiřina ; Říhová, Dagmar (advisor) ; Kocurková, Alena (referee)
The present work aims to familiarize students with current representatives of naked snails. In the Czech Republic there are five families of naked snails (Agriolimacidae, Arionidae, Boettgerillidae, Limacidae and Milacidae) and all their representatives are characterized by the loss of a secondary shell. Working closely represents ten of them. Part of the work is simplified determination dichotomous key and atlas. Basis of the thesis is a proposal of nine laboratory exercises, observations and experiments that pose naked snails from many angles, from basic observation of the external morphology through the food demands and sensory perception until after the autopsy. Tasks are designed for use in high school; Simplified variant may serve základoškolským hours practically oriented science. Some of the presented tasks (monitoring food preferences, sensory perception and response to stimuli) can be extended to a project day or protracted class of biologically oriented project. All designed tasks were tested. The most important model species of this thesis is the Spanish slug (Arion vulgaris (Moquin-Tandon, 1855)). It is a Czech non-native, invasive representative of the family Arionidae. Thanks laboratory exercises contained in the work of pupils, it is possible that the snail introduce in detail and...
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Food preferences and foraging mode in lizards (Squamata: Sauria)
Křivánek, Jan ; Gregorovičová, Martina (advisor) ; Kubička, Lukáš (referee)
In terms of food-foraging, lizards usually occupy one of two possible strategies ("foraging mode"). The first one is called "sit and wait" and it is defined by waiting on one position for a long time with a minimum movements and attack is based on visual cues on prey which gets to a certain distance. The second one is the "active foraging" in which the predator moves through terrain and it detects with help of chemical cues by nasal olfactoric system or vomeronasal system, with which is able to find a prey. Sometimes the third mode is also presented as a transition - "saltatory foraging" or a continuum between two these extreme strategies. Specific variables, which reflects the activity of a predator, are used to determine the "foraging mode" - MPM, PTM, PAM and AD. Within these predators a whole set of sensory adaptations ( such as enlarged olfactory lobes, a large abundance of taste buds, two fovea centralis in macula), morphological adaptations (e.g.shortening of the jaw, slender body morphology, forked tongue) and food adaptations (yellow color preference, ontogenetic shift to herbivory) are presented. Powered by TCPDF (www.tcpdf.org)
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Status of the flatworm Crenobia alpina in the food network of a spring
Reslová, Marie ; Simon, Ondřej (advisor) ; Černý, Martin (referee)
This work focuses on food preferences of freshwater triclad Crenobia alpina and its position in spring food web. It explores the ability of C. alpina to capture living prey, considers ability of C. alpina and to survive feeding on several types of food. Furthermore it gives view on its occurence and ecological preferences in context of other spring species. One chapter is concerned with taxonomy, anatomy and ecology of Tricladida and C. alpina itself. Short term food-preference experiments show the ability of C. alpina to capture living Lumriculidae and larvae of Ephemeroptera. We don't confirm feeding of C. alpina on living Gammarus, although their occurence in our springs and ecological preferences are similar. C. alpina feeds significantly more on damaged prey without substantial afinity to any species. A year-long experiment on C. alpina in lab conditions finds that this flatworm is able to survive and even breed with nothing but filtred water. This fact connected with the observation of huge densities of flatworms in spring source, opens up a question whether C. alpina can be considered a real predator. Key words: Crenobia alpina, triclad flatworms, food preferences, spring
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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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Food preferences of land snails in a river flood-plain invoved with invasive plants
Ševčíková, Štěpánka ; Juřičková, Lucie (advisor) ; Čejka, Tomáš (referee)
Food preferences to five most widespread invasive plant species from river floodplains: Impatiens glandulifera, Helianthus tuberosus, Fallopia japonica, F. sachalinensis a F.x bohemica and one native species - U. dioica were studied on two common land snail species. Using three different methods I tried to recognize, whether or not these plants serve as a food source to Succinea putris and Urticicola umbrosus. From histological sectionsit was impossible to identify the plants. The majority of plants don`t provide structures usable for identification of plant in the snail maces. I was able to identify only H. tuberosus and U. dioica undoubtedly, thanks to trichomes. According to the results of laboratory tests, the most important factors for snails food preferences are plant species and the condition of plant material. U. umbrosus consumed much less fresh material than S. putris. Consumption of frozen leaves became larger for both species. The most preffered plant species were U. dioica and H. tuberosus. Only frozen I. glandulifera was consumed. Fallopia spp. were rejected both, fresh or frozen.
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A comparison of selected ethological aspects of chosen tortoise species
BLAŽEK, David
In this thesis we studied individuals of 4 species of tortoises, often bred in captivity genus Testudo species T. hermanni, T. graeca, T. horsfieldi and T. marginata, in possession of the ZOO Hluboká nad Vltavou. We studied and analyzed their morphological parameters, size measurements, their weight and biometrical indexes, wheather they follow described sexual dimorphism as it was found out in non-captive populations. We also studied and analyzed their food preferences to find out differences between sexes and between keeping individual animal versus a group, by giving them a choice between 4 types of food (the red cabbage, leaves of dandelion and clover, and carrot roots). Sexual dimorphism displayed by different body proportions was most apparent in Testudo hermanni. In specimen from the ZOO of Testudo horsfieldi a T. graeca was sexual dimorphism less prominent. Measured Testudo females from the ZOO were in lowest, approximate and highest values bigger and heavier than males of the same species, which mirrors data from other studies of non-captive populations. Males are quicker to get to and quicker to start eating food than females. Males preffered red cabbage and carrot while the females clover and dandelion. The amplitude of preference change between individual and group experiment was not correlated by individual´s sex, species or size. We found out no apparent hierarchical enforcement from the side of faster or bigger specimen in the feeding process.
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