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Visar resultat 1 - 5 av 13 uppsatser som matchar ovanstående sökkriterier.

  1. 1. Assortativ parning hos sik (Coregonus lavaretus)

    Kandidat-uppsats, Umeå universitet/Institutionen för ekologi, miljö och geovetenskap

    Författare :Joni Riihimaa; [2022]
    Nyckelord :assortative mating; European whitefish; reproductive isolation;

    Sammanfattning : European whitefish (Coregonus lavaretus) forms reproductively isolated sub-populations with different body sizes in the lakes where northern pike (Esox lucius) exists. It has been hypothesized that the initial reproductive isolation between ecotypes arises through size-assortative mate choice or because small and large individuals arrive to the spawning grounds at different times. LÄS MER

  3. 2. Associations between body size polymorphism in Arctic charr and benthic invertebrate communities – clues to mechanisms for population differentiation?

    Master-uppsats, SLU/Dept. of Wildlife, Fish and Environmental Studies

    Författare :Andreas Sund; [2022]
    Nyckelord :arctic charr; benthic invertebrates; polymorphism;

    Sammanfattning : Many fish populations in the north have divided into coexisting ecotypes that differ in body size. While such polymorphic fish populations have been studied for many years, the understanding of how different types of selection contribute to the formation of dwarf- and giant ecotypes remains limited. LÄS MER

  4. 3. Spridningsbegränsningar för sik (Coregonus lavaretus) : En GIS-baserad studie

    Kandidat-uppsats, Umeå universitet/Institutionen för ekologi, miljö och geovetenskap

    Författare :Aron Dynesius; [2021]
    Nyckelord :European whitefish; dispersal limitations; GIS; Slope.; Sik; spridningshinder; spridningsbegränsningar; lutning; geografiska informationssytem; Coregonus lavaretus;

    Sammanfattning : An important question in determining species composition in a lake is what species has had the chance to reach the lake in the first place. The aim of this study was to examine natural stream connectivity limitations for whitefish (Coregonus lavaretus) between lakes, and to contribute to the development and evaluation of GIS-based methods to answer this question. LÄS MER

  5. 4. Sympatric Divergence in Whitefish Dwarfs : An investigation of phenotype-environment correlations in whitefish dwarfs

    Kandidat-uppsats, Umeå universitet/Institutionen för ekologi, miljö och geovetenskap

    Författare :Olivia Eriksson; [2021]
    Nyckelord :;

    Sammanfattning : Recent studies have found populations of European Whitefish (Coregonus lavaretus) to be under the process of divergence induced by a predator (pike, Esox lucius). This has caused whitefish to diverge into similar ecotypes but in separate lakes. LÄS MER

  7. 5. Effects of whitefish speciation on piscivorous birds : A dietary study of piscivorous birds in central and northern Sweden

    Master-uppsats, Umeå universitet/Institutionen för ekologi, miljö och geovetenskap

    Författare :Erik Söderlund; [2021]
    Nyckelord :Coregonus lavaretus; piscivorous; birds; diet; speciation;

    Sammanfattning : The ecological communities we observe today are a product of the bidirectional interactions between ecological and evolutionary processes. Although the effects of ecological processes on population divergence and speciation have been studied extensively, far less is known about the effects of divergence and speciation on ecological dynamics. LÄS MER