Search for dissertations about: "spawning"

Showing result 1 - 5 of 67 swedish dissertations containing the word spawning.

2. 1. Growth hormone and somatolactin function during sexual maturation of female Atlantic salmon

   Author : Susana Benedet Perea; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Growth hormone; somatolactin; insulin-like growth factor I; GH; SL; IGFI; GHR; SLR; IGFIR; ovary maturation; reproduction; Atlantic salmon; spawning; pituitary;

   Abstract : Background and aims: The growth hormone-insulin-like growth factor I (GH-IGF-I) system is known to act during sexual maturation of female salmonids, but the specific roles are not known. Somatolactin (SL) is a pituitary hormone closely related to GH and is only found in fish. In some species, including salmonids, there are two forms, SLa and SLß. READ MORE

4. 2. Reproductive pattern and offspring performance in brown trout (Salmo trutta)

   Author : Hans Olofsson; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biology; Salmo trutta; spawning; egg size; fry competition; fry dispersion; Biologi; Biology; Biologi; limnologi; Limnology;

   Abstract : This thesis deals with how reproductive traits and reproductive behaviour in femalebrown trout (Salmo trutta) are linked to offspring performance.In the small stream Tullviksbäcken, the choice of spawning sites was stronglyinfluenced by short-term fluctuations in stream flow and by substrate quality. READ MORE

5. 3. Conservation of landlocked Atlantic salmon in a regulated river : Behaviour of migratory spawners and juveniles

   Author : Anna Hagelin; Eva Bergman; Fleming Ian; Karlstads universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Atlantic salmon; conservation; migration; spawning; hydropower; competition; juveniles; brown trout; hatchery reared; fallback; delay; Biology; Biologi;

   Abstract : Hydropower dams represent one of the major threats to river ecosystems today. The dams block migratory routes in many rivers, which is problematic for migratory fish species. Trap-and-transport may be an alternative to fish passage solutions, as a strategy to compensate for lost river connectivity. READ MORE

6. 4. Spatial Modelling of Coastal Fish – Methods and Applications

   Author : Göran Sundblad; Ulf Bergström; Alfred Sandström; Peter Eklöv; Christian Möllmann; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; habitat; niche; species distribution modelling; juvenile; fish; larvae; spawning; Marine ecology; Marin ekologi; NATURAL SCIENCES; NATURVETENSKAP; Freshwater ecology; Limnisk ekologi; Biology; Biologi; Biology with specialization in Limnology; Biologi med inriktning mot limnologi; Biologi med inriktning mot zooekologi; Biology with specialization in Animal Ecology; Limnologi; Limnology;

   Abstract : Environmental factors influence species and habitats on multiple scales creating a mosaic of distribution patterns. Studying factors shaping these patterns are central to our understanding of population dynamics and ultimately ecosystem functioning. READ MORE

7. 5. The spawning salmon as a resource by recreational use : the case of the wild Baltic salmon and conditions for angling in north Swedish rivers

   Author : Håkan Appelblad; Umeå universitet; []
   Keywords : SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Baltic salmon; Wild salmon; Angling; Fishing tourists; Natural resource; Upper Norrland; Sweden; Social and Economic Geography; kulturgeografi;

   Abstract : The aim of the thesis is to analyse the preconditions for increasedsalmon angling in the remaining wild salmon rivers in Upper Norrland in northernSweden, as well as to evaluate the present and possible future impacts on the localeconomy. It includes the identification of the internal and external conditions, in what ishere called the Salmon Utilisation Landscape, that influence the present use as well asfuture development of the Baltic salmon as a resource in angling. READ MORE