Sökning: "stream salmonids"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden stream salmonids.

1. 1. Winter behaviour of stream salmonids: effects of temperature, light, and ice cover

   Författare :Johan Watz; Larry Greenberg; Eva Bergman; John Piccolo; Svein Jakob Saltveit; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stream salmonids; winter behaviour; efftect of temperatur; light; ice cover; environment; fish populations; Biology; Biologi;

   Sammanfattning : In boreal streams, stream salmonids typically face low water temperatures and variable ice conditions during winter, and thus stream salmonids are expected to use different behavioural strategies to cope with these environmental conditions. The studies presented in this thesis explore how temperature, light intensity, and surface ice affect salmonid behaviour, with focus on drift-feeding and ventilation rates. LÄS MER

3. 2. Salmonid behaviour under winter conditions

   Författare :Johan Watz; Larry Greenberg; Eva Bergman; John Piccolo; Richard Cunjak; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; climate change; drift; energy budget; foraging; grayling; ice cover; lotic; metabolic rate; predation; salmon; stream; stress; temperature; trout; Biology; Biologi;

   Sammanfattning : Winter conditions are believed to play an important role in the population dynamics of northern temperate stream fish, challenging the ability of fish to physiologically and behaviourally adapt. Climate change is predicted to increase both mean temperature and temperature fluctuations, especially during winter, leading to dynamic environmental conditions in terms of river ice production and flow. LÄS MER

4. 3. Effects of fine woody debris on juvenile brown trout (Salmo trutta) and drifting invertebrates

   Författare :Åsa Enefalk; Eva Bergman; Siân Griffiths; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; brown trout; juvenile; stream; woody debris; invertebrates; fine woody debris; Biology; Biologi;

   Sammanfattning : In boreal forest streams, woody debris is an important habitat component. Stream invertebrates and salmonids such as brown trout benefit from in-stream wood. LÄS MER

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

   Författare :Karl Filipsson; Eva Bergman; Ann Erlandsson; Martin Österling; Johan Watz; Stefán Óli Steingrímsson; Karlstads universitet; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

7. 5. Pheromonal Mediated Behaviour and Endocrine Responses in Salmonids : The impact of Cypermethrin, Copper, and Glyphosate

   Författare :Alia Jaensson; Ingvar Brandt; Håkan Olsen; Kjell Döving; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Cypermethrin; copper; glyphosate; behaviour; hormones; pheromones; olfaction; 11-ketotestosterone 11-KT ; 17α; 20β-dihydroxy-4-pregnen-3-one 17; 20β-P ; reproduction; Toxicology; Toxikologi; Biologi med inriktning mot ekotoxikologi; Biology with specialization in Environmental Toxicology;

   Sammanfattning : The effects of cypermethrin, copper and glyphosate on the endocrine system and subsequent response to female pheromones were investigated in mature male brown trout (Salmo trutta) parr.  Responses measured were the amount of strippable milt, blood plasma levels of both an androgen (11-ketotestosterone (11-KT)) and a progestin (17α,20β-dihydroxy-4-pregnen-3-one (17,20b-P)), and behavioural changes. LÄS MER