Search for dissertations about: "mayflies"
Found 5 swedish dissertations containing the word mayflies.
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1. The function of seasonal habitat shifts in two congeneric mayflies in a boreal river
Abstract : Unregulated North Swedish rivers show large seasonal variations in their physical characteristics. During winter the whole littoral zone freezes solid, and in spring the water flow increases rapidly and the same areas become flooded. The two mayflies Parameletus chelifer and P. minor are common in the North Swedish river Vindelälven. READ MORE
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2. Ecology of freshwater mussels in disturbed environments
Abstract : The number of species extinctions is increasing at an alarming rate. Long-lived freshwater mussels of the order Unionoida, which include a parasitic stage on a host fish, are highly threatened. Habitat degradation by turbidity and sedimentation is thought to be one major reason for their decline. READ MORE
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3. Visual ecology of insect superposition eyes
Abstract : In the superposition compound eye each rhabdom (light sensitive unit) receives light through many ommatidial facets, while in the apposition compound eye every rhabdom receives light from a single facet. The superposition design increases photon capture, which is an advantage in dark environments. READ MORE
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4. Molecular phylogenetics and taxonomic issues in dragonfly systematics (Insecta: Odonata)
Abstract : Dragonflies (Odonata) are one of the ancestral groups of extant insects. They represent one of the three most basal branches in the phylogeny of winged insects. The other two groups are the Ephemeroptera, mayflies, and Neoptera, the latter which covers the remaining winged insects. READ MORE
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5. Lateral movements versus stationarity : adaptive alternatives in benthic invertebrates to the seasonal environment in a boreal river
Abstract : Benthic invertebrates inhabiting boreal rivers are exposed to very large seasonal variations in their physical environment. The extremes are in winter when the littoral area freezes solid and in spring when water flow increases rapidly. READ MORE