Search for dissertations about: "Hydrobiology"

Showing result 16 - 20 of 37 swedish dissertations containing the word Hydrobiology.

  2. 16. Local adaptive pigmentation in Asellus aquaticus -effects of UV-radiation and predation regime

    Author : Jonas Johansson; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Marinbiologi; limnology; aquatic ecology; marine biology; Hydrobiology; Ekologi; Ecology; damselfly; perch; UV-avoidance; isopod; anti-predator traits; evolution; selective predation; limnologi; akvatisk ekologi; Animal ecology; Djurekologi;

    Abstract : Pigmentation in the freshwater isopod Asellus aquaticus differed between two habitats. Asellus were lighter pigmented in stands of submerged stonewort vegetation, than in nearby reed stands. Moreover, Asellus pigmentation became lighter with time in recently established stonewort stands. READ MORE

  4. 17. Ecological implications of the production of toxic substances by fish killing phytoplankton species grown under variable N:P-ratios

    Author : Niclas Johansson; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; mixotrophy; grazing; allelopathic interactions; allelopathy; algae; phytoplankton; nutrient limitation; toxicity; Toxic haptophytes; fishkilling phytoplankton; Hydrobiology; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

    Abstract : The influence of different nutrient conditions on the production of toxins was studied in certain fishkilling haptophytes (e.g. Prymnesium parvum and Chrysochromulina polylepis). READ MORE

  5. 18. Allochthonous and autochthonous carbon sources of lake bacterioplankton

    Author : Emma Kritzberg; Enhet akvatisk ekologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Marinbiologi; limnologi; akvatisk ekologi; aquatic ecology; marine biology; Hydrobiology; bacterial community composition; bacterial growth efficiency; bacterioplankton; carbon subsidy; dissolved organic carbon; limnology;

    Abstract : Organic substrates for pelagic bacteria are derived from dissolved organic carbon (DOC) in the water column that originates either from primary production from within the lake itself (autochthonous), or import of organic matter from the terrestrial watershed (allochthonous production). This thesis addresses the utilization of allochthonous versus autochthonous carbon (C) sources by lake bacterioplankton. READ MORE

  6. 19. Waterfowl in temperate eutrophic lakes - Interactions with macroinvertebrates, submerged vegetation and fish

    Author : Ola Marklund; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Hydrobiology; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; Chara; Asellus; chironomidae; ultraviolet radiation; epiphytes; predation; herbivory; diel vertical migration; fish; Waterfowl; macroinvertebrates; submerged vegetation;

    Abstract : The aim of this thesis was to explore some of the important links between waterfowl and the biota in shallow eutrophic lakes in temperate areas. Waterfowl depend on macroinvertebrates as sources of protein and calcium, which are essential for egg production and growth. Macroinvertebrates in turn depend on submerged vegetation for food and shelter. READ MORE

  7. 20. The Cyanophyte Arthrospira Fusiformis in African Waters - Eco-Physiology and Potential Use in Tropical Aquaculture

    Author : Aidate Mussagy; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; limnology; Marinbiologi; marine biology; aquatic ecology; lipopolysaccharide endotoxins LPS ; salinity; osmoregulation; proline; aquaculture feeds; Artemia.; Hydrobiology; anatoxin; microcystin; ITS sequences; phenotype analysis; taxonomy; Cyanophyceae; Arthrospira fusiformis; limnologi; akvatisk ekologi;

    Abstract : The cyanoprokaryote (blue-green algae) genus Arthrospira occurs in saline, alkaline tropical waters of Africa, Asia, and Central America. Traditionally Arthrospira has been used as a food supplement by the Kanembu tribe of Lake Chad and Aztecs living in the valley of Mexico City. READ MORE