Sökning: "Perch"

Visar resultat 1 - 5 av 71 avhandlingar innehållade ordet Perch.

  1. 1. Population divergence at small spatial scales – theoretical and empirical investigations in perch

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Sara Bergek; Mats Björklund; Teija Aho; Sarah Goodacre; [2009]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Perca fluviatilis L.; Perch; Small scale genetic differentiation; Morphometrics; Isolation by distance; Dispersal; Gene flow; Microsatellites; Spatiotemporal stability; Barriers; NATURAL SCIENCES Biology; NATURVETENSKAP Biologi; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology; NATURVETENSKAP Biologi Terrestrisk; limnisk och marin ekologi; Animal Ecology; zooekologi;

    Sammanfattning : Genetically structured populations arise when gene flow between groups of individuals is hindered by geographical, behavioural or temporal barriers. The identification of such groups is important for understanding evolution and has large implications for conservation concern. LÄS MER

  3. 2. Population ecology of perch (Perca fluviatilis) in boreal lakes

    Detta är en avhandling från Karlstad : Karlstad University

    Författare :Arne Linløkken; Eva Bergman; Larry Greenberg; Anders Hargeby; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; perch; growth; size; mortality; temperature; acidification; density; roach; competition; NATURAL SCIENCES Biology; NATURVETENSKAP Biologi; Biology; Biologi;

    Sammanfattning : I studied the effects of temperature, pH, competition and predation on Eurasian perch (Perca fluviatilis) in 30 lakes in Norway during 1981-2001. The study lakes were situated in two different areas in southern Norway; four lakes in Aust-Agder county in southernmost Norway were explored during 1981-1984 and 26 lakes in Hedmark county in south-eastern Norway were investigated during 1992-2001. LÄS MER

  4. 3. Interplay Between Environment and Genes on Morphological Variation in Perch – Implications for Resource Polymorphisms

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Jens Olsson; Uppsala universitet.; [2006]
    Nyckelord :Ecology; Perch; Resource polymorphism; Genetic differentiation; Phenotypic plasticity; Morphology; Competition; Character divergence; Behavior; Growth rate; Resource level; Gut lenght; Ekologi;

    Sammanfattning : Recent research has suggested that individual specialization within populations could be substantial and more common than previously acknowledged. Eurasian perch is one of many species of fish in lakes of postglacial origin that displays a morphological and dietary variation tightly coupled to the littoral and pelagic habitats of the lake. LÄS MER

  5. 4. Biomarkers in perch (Perca fluviatilis) used in environmental monitoring of the Stockholm recipient and background areas in the Baltic Sea

    Detta är en avhandling från Stockholm : Institutionen för tillämpad miljövetenskap (ITM)

    Författare :Tomas Hansson; Lennart Balk; Ulf Rannug; Tracy Collier; ; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; biomarker; DDT; environmental monitoring; EROD; fish; GSI; nanoinjection; PAH; PCB; Perca fluviatilis; perch; reproduction; NATURAL SCIENCES Chemistry Environmental chemistry Environmental toxicology; NATURVETENSKAP Kemi Miljökemi Miljötoxikologi; Applied Environmental Science; tillämpad miljövetenskap;

    Sammanfattning : This thesis reports the results of biomarker measurements in three environmental monitoring projects. In the first project, which was part of the Swedish national environmental monitoring, biomarkers were measured annually in female perch (Perca fluviatilis) in two background areas in the Baltic Sea during 1988–2000, resulting in a unique 13-year series of measurements. LÄS MER

  7. 5. Ecology and Evolution of Adaptive Morphological Variation in Fish Populations

    Detta är en avhandling från Umeå : Umeå universitet

    Författare :Richard Svanbäck; Peter Eklöv; Lennart Persson; Beren Robinson; [2004]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; competition; functional morphology; individual specialization; inter-individual variation; intra-population variation; morphological variation; ontogeny; Perca fluviatilis; perch; phenotypic plasticity; predation; trade-offs; Ekologi; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology; NATURVETENSKAP Biologi Terrestisk; limnisk och marin ekologi;

    Sammanfattning : The work in this thesis deals with the ecology and evolution of adaptive individual variation. Ecologists have long used niche theory to describe the ecology of a species as a whole, treating conspecific individuals as ecological equivalent. LÄS MER