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Showing result 1 - 5 of 52 swedish dissertations matching the above criteria.

  2. 1. Parasite on Crayfish : Characterisation of Their Pathogenesis, Host Interactions and Diversity

    Author : Eakaphun Bangyeekhun; Anders Tunlid; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Zoophysiology; Crayfish; Parasite; Oomycete; Prophenoloxidase; Peroxinectin; Aphanomyces astaci; Psorospermium haecheli; White spot syndrome virus; Zoofysiologi; Animal physiology; Zoofysiologi; biologisk beroendeforskning; Biological Research on Drug Dependence;

    Abstract : The crayfish plague refractory crayfish, Pacifastacus leniusculus, which can harbour the fungal parasite within melanotic sheath, are found to constitutively express the gene encoding for prophenoloxidase (proPO) after mimicking parasite attack. In contrast, the susceptible crayfish, Astacus astacus, responds to the parasite by increased levels of proPO transcript, particularly in the semigranular haemocytes. READ MORE

  4. 2. Immune defense reactions in freshwater crayfish : Cellular components

    Author : Charlotta Ekblom; Irene Söderhäll; Kallaya Sritunyalucksana-Dangtip; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; crustaceans; hemocytes; immunity; crayfish; proteomics; transcriptomics; Biology with specialization in Comparative Physiology; Biologi med inriktning mot jämförande fysiologi;

    Abstract : The freshwater signal crayfish, Pacifastacus leniusculus, is a well-established model for studying the immune system of invertebrates. Many important discoveries have been made in this species, among others related to the clotting reaction, hematopoiesis, the prophenoloxidase activating system, the functions of crustacean immune cells, and pathogen recognition. READ MORE

  5. 3. Dynamics of omnivorous crayfish in freshwater ecosystems

    Author : Karin Olsson; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; crayfish; freshwater ecosystems; niche width; growth rate; stable isotope analysis; recruitment; RNA:DNA analysis; Ecology; food availability and quality; trophic position; population dynamics;

    Abstract : In this thesis I examine the dynamics of crayfish in streams and lakes. I have studied the influence of abiotic and biotic factors on abundance, growth, trophic position, niche breadth, and recruitment of crayfish, by conducting field studies, an outdoor channel experiment and timeseries analysis. READ MORE

  6. 4. The different roles of crayfish in benthic food webs

    Author : Patrik Stenroth; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Marinbiologi; limnologi; aquatic ecology; marine biology; food chain length; stable isotopes; environmental gradients; diet; crayfish; akvatisk ekologi; limnology; Hydrobiology;

    Abstract : I show that crayfish consume detritus, algae, macrophytes, and an array of invertebrates. Crayfish were found to reduce invertebrate densities. However, prey mobility seemed to be a key factor regulating the strength of interactions between crayfish and prey. READ MORE

  7. 5. White Spot Syndrome Virus Interaction with a Freshwater Crayfish

    Author : Pikul Jiravanichpaisal; Kenneth Söderhäll; Irene Söderhäll; Ellen Kauschke; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biology; WSSV; crayfish; hematopoietic tissue; cytokine; innate immunity; hemocytes; Biologi; Biology; Biologi;

    Abstract : Viruses are very abundant in water and hence diseases caused by viruses are common in marine organisms. These diseases create great problems for the commercial farming of crustaceans and mussels. READ MORE