Sökning: "limnology"

Visar resultat 41 - 45 av 94 avhandlingar innehållade ordet limnology.

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

    Författare :Aidate Mussagy; Biologiska institutionen; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  3. 42. Lake bathymetry as driver of salmonid population size structure and biomass

    Författare :Sven Norman; Pär Byström; Karin A. Nilsson; Jan Karlsson; Per-Arne Amundsen; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lake bathymetry; habitat-specific resource production; ontogenetic niche shifts; size structure; Arctic char; brown trout; populationsbiologi; Population Biology; Limnology; limnologi; zooekologi; Animal Ecology;

    Sammanfattning : Most fish species undergo ontogenetic niche shifts from feeding on pelagic zooplankton, to larger benthic invertebrates and in some cases also to fish. These ontogenetic niche shifts have strong impact on the interactions within and between species, with effects on individual growth, population abundance and food web dynamics. LÄS MER

  4. 43. The effects of crayfish on interactions in freshwater benthic communities

    Författare :Per Nyström; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; exotic species; trophic cascades; omnivory; crayfish; Trophic interactions; freshwater; Hydrobiology; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

    Sammanfattning : This thesis examines how freshwater crayfish affect community interactions in benthic food webs. I have mainly studied the influence of the introduced signal crayfish (Pacifastacus leniusculus) on littoral communities, but also the influence of the native noble crayfish (Astacus astacus). LÄS MER

  5. 44. Reproductive pattern and offspring performance in brown trout (Salmo trutta)

    Författare :Hans Olofsson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Salmo trutta; spawning; egg size; fry competition; fry dispersion; Biologi; Biology; Biologi; limnologi; Limnology;

    Sammanfattning : This thesis deals with how reproductive traits and reproductive behaviour in femalebrown trout (Salmo trutta) are linked to offspring performance.In the small stream Tullviksbäcken, the choice of spawning sites was stronglyinfluenced by short-term fluctuations in stream flow and by substrate quality. LÄS MER

  7. 45. Consumption patterns and excretion in aquatic food websenrichment

    Författare :Anders Persson; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hydrobiology; trophic interactions; translocation; biomanipulation; enrichment; phosphorus; model; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

    Sammanfattning : This thesis links biogeochemical cycling to classical ecology. Predictions derived from food chain theory, based on Lotka-Volterra type of interactions, were tested in aquatic environments with the main hypothesis that consumers affect lower levels of organization by both predation and excretion of limiting nutrients. LÄS MER