Search for dissertations about: "Arctic char"

Showing result 1 - 5 of 7 swedish dissertations containing the words Arctic char.

  1. 1. Evolutionary ecology of arctic char (Salvelinus alpinus (L.)) : Intra- and interspecific interactions in circumpolar populations

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Johan Hammar; Uppsala universitet.; [1998]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; Arctic char; Salvelinus alpinus; biogeography; niche; life history; population ecology; intra- and interspecific interactions; cannibalism; competition; landlocked; marginal populations; species border; Ekologi; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology; NATURVETENSKAP Biologi Terrestisk; limnisk och marin ekologi; Animal Ecology; zooekologi;

    Abstract : This thesis examines a suite of ecological and genetic mechanisms influencing the fundamental and realized niche borders of European and North American populations of the Arctic char (Salvelinus alpinus (L.)) species complex in allopatry as well as in sympatry with brown trout (Salmo trutta) or brook trout (Salvelinus fontinalis). READ MORE

  2. 2. Invasion of top and intermediate consumers in a size structured fish community

    University dissertation from Umeå : Umeå universitet, Institutionen för ekologi, miljö och geovetenskap

    Author : Per Ask; Umeå universitet.; [2010]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Invasion; intraguild predation; size-structure; cannibalism; climate; temperature; Arctic char; ninespine stickleback; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology Freshwater ecology; NATURVETENSKAP Biologi Terrestrisk; limnisk och marin ekologi Limnisk ekologi; biology; biologi;

    Abstract : In this thesis I have investigated the effects of invading top and intermediate consumers in a size-structured fish community, using a combination of field studies, a lake invasion experiment and smaller scale pond and aquaria experiments. The lake invasion experiment was based on introductions of an intermediate consumer, ninespine stickleback (Pungitius pungitius L. READ MORE

  3. 3. Developmental and reproductive regulation of NR5A genes in teleosts

    University dissertation from Umeå : Molekylärbiologi (Teknisk-naturvetenskaplig fakultet)

    Author : Jonas von Hofsten; Umeå universitet.; Umeå universitet.; [2004]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Cell and molecular biology; FTZ-F1; NR5A; zebrafish; teleost; arctic char; SF-1; LRH-1; fushi tarazu; Cell- och molekylärbiologi; NATURAL SCIENCES Biology Cell and molecular biology; NATURVETENSKAP Biologi Cell- och molekylärbiologi; molekylärbiologi; Molecular Biology;

    Abstract : In mammals sex chromosomes direct and initiate the development of male and female gonads and subsequently secondary sex characteristics. In most vertebrates each individual is pre-destined to either become male or female. READ MORE

  4. 4. Teleost reproduction: Aspects of Arctic char (Salvelinus alpinus) oocyte growth and maturation

    University dissertation from Umeå : Molekylärbiologi (Teknisk-naturvetenskaplig fakultet)

    Author : Håkan Berg; Umeå universitet.; Umeå universitet.; [2003]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Zoophysiology; Salmonid; oocyte growth; vitellogenin; vitelline envelope protein; stress; cortisol; oocyte maturation; membrane receptor; Zoofysiologi; NATURAL SCIENCES Biology Organism biology Animal physiology; NATURVETENSKAP Biologi Organismbiologi Zoofysiologi; Zoophysiology; zoofysiologi;

    Abstract : In all vertebrate species, reproduction is a hormonally controlled process, important for growth and maturation of gonads and germ cells. Production of functional germ cells is of outmost importance to secure the survival of a species. Fish comprises 50% of the known vertebrates and are found in aquatic habitats all over the world. READ MORE

  5. 5. Behavioural and Neuroendocrine Effects of Stress in Salmonid Fish

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Øyvind Øverli; Uppsala universitet.; [2001]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Aggression; Behaviour; Brain; Coping; Cortisol; Dominance; Dopamine; Feeding; Hierarchy; Norepinephrine; Responsiveness; Serotonin; Utvecklingsbiologi; NATURAL SCIENCES Biology Organism biology Developmental biology; NATURVETENSKAP Biologi Organismbiologi Utvecklingsbiologi; Developmental Biology; miljömedicinsk utvecklingsbiologi;

    Abstract : Stress can affect several behavioural patterns, such as food intake and the general activity level of an animal. The central monoamine neurotransmitters serotonin, dopamine, and norepinephrine are important in the mediation of both behavioural and neuroendocrine stress effects. READ MORE