Search for dissertations about: "Perca fluviatilis"

Showing result 11 - 15 of 44 swedish dissertations containing the words Perca fluviatilis.

  2. 11. Distributions and competitive abilities of perch Perca fluviatilis and ruffe Gymnocephalus cernuus along environmental gradients

    Author : Eva Bergman; Lunds universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biology; Biologi;

    Abstract : .... READ MORE

  4. 12. Nutrition of Arctic charr (Salvelinus alpinus) and Eurasian perch (Perca fluviatilis) and evaluation of alternative protein sources

    Author : Markus Langeland; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Abstract : The aim of this thesis was to estimate the dietary lysine requirement of Eurasian perch (Perca fluviatilis), to study the digestive enzyme activity in perch and Arctic charr (Salvelinus alpinus) and the utilization of meals of microbial and mussel meals. Juvenile Eurasian perch were fed semi-purified diets containing graded levels of lysine (12. READ MORE

  5. 13. Environmental influence on Hg and 137Cs levels in perch (Perca fluviatilis L.) and roach (Rutilus rutilus L.) from circumneutral lakes

    Author : Lars Sonesten; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biology; Hg; 137Cs; fish; PLS; land use; cations; humic substances; circumneutral; Biologi; Biology; Biologi; limnologi; Limnology;

    Abstract : Mercury and radioactive caesium have received immense attention in Sweden during the past decades, as common contaminants in fish. This thesis examines how the Hg and 137Cs levels in fish from 79 circumneutral lakes are affected by various environmental factors. READ MORE

  6. 14. Biological Diversity of Fish and Bacteria in Space and Time

    Author : Henrik Ragnarsson; Peter Eklöv; Kerstin Holmgren; Göran Englund; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; species richness; fish; lake; biogeography; glacial; colonization; metacommunity; speciation; perch; bacteria; diversity; Ekologi;

    Abstract : Biological diversity is controlled by an array of factors and processes all active at different spatial and temporal scales. Regional factors control what species are available to occur locally, whereas the local factors determine what species are actually capable of colonizing the locality. READ MORE

  7. 15. Psychotropic Pharmaceuticals in Aquatic Systems: An Ecological Perspective

    Author : Melanie Hedgespeth; Enhet akvatisk ekologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; ecotoxicology; aquatic; trophic level; pharmaceutical; SSRI; beta-blocker; sertraline; fluoxetine; propranolol; fish; daphnia; snail; predator; prey; behavior; life history; multiple stressor;

    Abstract : Psychotropic pharmaceuticals have been shown to exert a variety of sublethal effects on non-target organisms, even at low concentrations found in the environment (ng/L to µg/L); hence, the aim of my research has been to determine the individual-level effects of psychotropic pharmaceuticals (the selective serotonin reuptake inhibitors sertraline and fluoxetine, and the β-blocker propranolol) on behavioral and life history traits in freshwater organisms. Further, this research was directed towards assessing the potential large-scale impacts of these effects on population growth and predator-prey interactions (with community-level implications) via the application of traditional, ecological concepts and models. READ MORE