Description: Das Projekt "Daphnia hybrids" wird vom Umweltbundesamt gefördert und von Universität Konstanz, Limnologisches Institut durchgeführt. Hybrids of the water flea Daphnia occur in many lakes. However, little is known about the factors that cause the success of Daphnia hybrids. In a joint project of two laboratories we study the possible role of biotic interactions in the maintenance of a Daphnia hybrid complex. Daphnia hyalina, D. galeata and their hybrids occur in Bodensee and in Greifensee. The parent species are more abundant in Lake Constance, while hybrids dominate in Greifensee. Both lakes differ in important aspects (morphometry, trophic state), which is reflected by different biotic influences con Daphnia. Compared to Lake Constance, Daphnia in Greifensee are more often exposed to low quality food (toxic blue-greens) and have less of a refuge from fish predation (due the anoxic hypolimnion). Differences between both lakes in the invertebrate predation regime and in the parasite load of Daphnia are very probable. Besides field sampling programmes, we want to establish a collection of about 50 Daphnia clones from both lakes (parent species and hybrids, recent clones and old clones hatched from sediment cores). These clones will be used for life history experiments in the laboratory to test the influences of low quality food, of fish kairomones, of invertebrate predator kairomones and of a protozoan parasite. Food quality and invertebrate predator experiments will be done in Konstanz; parasite and fish experiments will be done in Dübendorf.
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Konstanz ? Krustazeen ? Populationsdynamik ? Speisefisch ? Fisch ? Morphometrie ? Seen ? Cyanobakterien ? Morphologie ? Nährstoff ? Zooplankton ? Bodensee ? Binnengewässer ? Biologie ? Biozönose ? Daphnien ? Fischtest ? Hypolimnion ? Wirbellose ? Limnisches Ökosystem ? Plankton ? Protozoen ? Räuber-Beute-Beziehung ? Sedimentkern ? Tierart ? Prädator ? Gewässerorganismen ? Vergleichsanalyse ? Duftstoff ? Parasit ? Mikroorganismen ? Sediment ? Nährstoffkreislauf ? Laborversuch ? Studie ? Ökosystemforschung ? Biologische Untersuchung ? Oberflächengewässer ? Trophiegrad ? Nahrungskette ? Probenahme ? Schichtung ? Lebensmittelqualität ? Biomasse ? Biomasseproduktion ? Daphnia hyalina ? Daphnia galeata ? Wachstum [biologisch] ? Greifensee ? Hybrid ? See [Binnengewässer] ?
Region: Baden-Württemberg
Bounding box: 9° .. 9° x 48.5° .. 48.5°
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 2002-01-01 - 2003-12-31
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