Sökning: "Gädda"

Visar resultat 1 - 5 av 7 avhandlingar innehållade ordet Gädda.

1. 1. Migratory behaviour and adaptive divergence in life-history traits of pike (Esox lucius)

   Författare :Petter Tibblin; Per Larsson; Anders Forsman; Asbjørn Vøllestad; Linnéuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; conservation; evolution; homing; local adaptation; management; phenotypic variation; population divergence; selection; sympatric;

   Sammanfattning : Population divergence shaped by natural selection is central to evolutionary ecology research and has been in focus since Darwin formulated “The origin of species”. Still, the process of adaptive divergence among sympatric populations is poorly understood. LÄS MER

3. 2. Intraspecific diversity of pike (Esox lucius) in the Baltic Sea and new insights on thermoregulation in fish

   Författare :Oscar Nordahl; Per Larsson; Anders Forsman; Juha Merilä; Linnéuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; adaptive divergence; Cyprinus carpio; ecology; Esox lucius; evolution; local adaptation; management; thermoregulation; sun-basking; vertical migration; Akvatisk ekologi; Aquatic Ecology; Evolutionary Biology; Evolutionsbiologi;

   Sammanfattning : Fish display a fascinating variation in behavior, morphology and physiology among species, among individuals within species, and within individuals over time. A central quest in ecology and evolution is to understand causes and consequences of such variation. LÄS MER

4. 3. Fish foraging under visual constraints

   Författare :Mikael Jönsson; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; planktivore.; piscivore; brownification; visual foraging; Turbidity;

   Sammanfattning : Visual conditions are changing in several different ways. Some lakes are getting turbid due to eutrophication or erosion while others are getting browner due to brownification. These two types of visual degradation results in completely different optical properties of lakes. LÄS MER

5. 4. Pikeivory: behavioural mechanisms in northern pike piscivory

   Författare :Anders Nilsson; Enhet akvatisk ekologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; northern pike; cannibalism; kleptoparasitism; predation; optimal foraging; Animal ecology; Djurekologi;

   Sammanfattning : Optimal foraging and prey preference in top predators may affect population and community dynamics and structure. Also, optimal foraging and prey preference may shift with prevailing conditions, and therefore create changes in the effect of predation. LÄS MER

7. 5. Phenotypic plasticity and the evolution of an inducible morphological defence in crucian carp

   Författare :Lars Pettersson; Biodiversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Animal ecology; Benefits; Costs; Predation; Chemical cues; Fish; Djurekologi;

   Sammanfattning : In this thesis, I have investigated factors (cues, benefits, and costs) affecting the evolution of an inducible morphological defence in crucian carp (Carassius carassius). Inducible defences are favoured over permanent defences when prey have reliable cues to detect predators, when defences are effective but costly, and when predation pressure is variable and unpredictable, but sometimes strong. LÄS MER