Search for dissertations about: "PISCIVOROUS PREDATORS"

Showing result 1 - 5 of 7 swedish dissertations containing the words PISCIVOROUS PREDATORS.

  2. 1. Early life stages of brown trout - Anti-predator responses under warming winters

    Author : Karl Filipsson; Eva Bergman; Ann Erlandsson; Johan Watz; Martin Österling; Neil Metcalfe; Karlstads universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; behaviour; climate; cortisol; development; egg incubation; embryo; gene expression; ice; light; mRNA; piscivorous; poikilotherm; salmonid; stress; temperature; Biology; Biologi;

    Abstract : During winter, juvenile salmonids in boreal streams are vulnerable to predation, mainly from mammals and birds. Encounters with terrestrial predators can be reduced or avoided if fish limit activity to the darker periods of the day or to periods with surface ice. READ MORE

  4. 2. From behaviour to genes: anti-predator responses of brown trout (Salmo trutta) under winter conditions

    Author : Karl Filipsson; Eva Bergman; Ann Erlandsson; Martin Österling; Johan Watz; Stefán Óli Steingrímsson; Karlstads universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; burbot; climate change; cortisol; diel behaviour; gene expression; HPI axis; light; mRNA; piscivorous; poikilotherm; predator; salmonid; stream; stress; temperature; thermal; winter behaviour; Biology; Biologi;

    Abstract : Temperature has major effects on the performance of poikilotherms. In encounters with predators, low winter temperatures constrain predator detection and escape capabilities in prey fishes. READ MORE

  5. 3. Foraging behaviour in piscivorous fish: mechanisms and patterns

    Author : Håkan Turesson; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; marine biology; Hydrobiology; piscivory; consumption rate; confusion effect; capture success; predation; encounter rate; prey choice;

    Abstract : Mechanistic understanding of piscivore foraging at the individual level is important in order to understand and make predictions of piscivore effects at population and community levels. To understand the mechanisms affecting selection and consumption rates each step in the foraging cycle (search, encounter, active choice, attack, capture, ingestion, digestion) should be studied. READ MORE

  6. 4. Phenotypic plasticity and the evolution of an inducible morphological defence in crucian carp

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

    Abstract : 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. READ MORE

  7. 5. Habitat selection and indirect interactions in fish communities : mechanisms to explain spatial distribution of perch, roach, and vendace

    Author : Ulrika Beier; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : To increase the understanding of freshwater lake ecosystems, I have studied the habitat selection of perch (Perca fluviatilis L.), roach (Rutilus rutilus (L.)), and vendace (Coregonus albula (L.)). READ MORE