Browsing NTNU Open by Author "Einum, Sigurd"
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Assessing risks of invasion through gamete performance: Farm Atlantic salmon sperm and eggs show equivalence in function, fertility, compatibility and competitiveness to wild Atlantic salmon
Yeates, Sarah E.; Einum, Sigurd; Fleming, Ian A.; Holt, William V.; Gage, Matthew J.G. (Journal article; Peer reviewed, 2014)Adaptations at the gamete level (a) evolve quickly, (b) appear sensitive to inbreeding and outbreeding and (c) have important influences on potential to reproduce. We apply this understanding to problems posed by escaped ... -
Automated measurement of upper thermal limits in small aquatic animals
Burton, Tim; Zeis, Bettina; Einum, Sigurd (Journal article; Peer reviewed, 2018)We present a method for automating the measurement of upper thermal limits in small aquatic organisms. Upper thermal limits are frequently defined by the cessation of movement at high temperature, with measurement being ... -
Can variation in standard metabolic rate explain context- dependent performance of farmed Atlantic salmon offspring?
Robertsen, Grethe; Reid, Donald; Einum, Sigurd; Aronsen, Tonje; Fleming, Ian A.; Sundt-Hansen, Line Elisabeth Breivik; Karlsson, Sten; Kvingedal, Eli; Ugedal, Ola; Hindar, Kjetil (Journal article; Peer reviewed, 2018)Escaped farmed Atlantic salmon interbreed with wild Atlantic salmon, leaving off- spring that often have lower success in nature than pure wild salmon. On top of this, presence of farmed salmon descendants can impair ... -
Change in Thermal Metabolic Rate Reaction Norms of Daphnia in Response to Rearing Temperature
Gajic, Tijana (Master thesis, 2013)Temperature is an important environmental factor that affects the distribution of organisms. It affects the biochemical and physiological processes which are the basis of life. The metabolic cold adaptation (MCA) hypothesis ... -
Cryptic choice of conspecific sperm controlled by the impact of ovarian fluid on sperm swimming behavior
Yeates, SE; Diamond, SE; Einum, Sigurd; Emerson, Brent C.; Holt, WV; Gage, MJG (Journal article; Peer reviewed, 2013)Despite evidence that variation in male–female reproductive compatibility exists in many fertilization systems, identifying mechanisms of cryptic female choice at the gamete level has been a challenge. Here, under risks ... -
Density effect on growth rate of juvenile Atlantic salmon (Salmo salar) in manipulated large rivers
Vae, Eivind (Master thesis, 2015)Growth rate of young-of-the-year (YOY) Atlantic salmon (Salmo salar) in low-density rivers was substantial better relative to YOY captured in normal density rivers. Mean growth index ± SD for YOY in low-density rivers was ... -
Density independent use of shallow riverine areas in juvenile Atlantic salmon
Puffer, Michael; Berg, Ole Kristian; Hamnes, Frøydis Bolme; Bentsen, Vidar; Koch, Wouter; Ugedal, Ola; Forseth, Torbjørn; Arnekleiv, Jo Vegar; Einum, Sigurd (Journal article; Peer reviewed, 2018)Habitat use of aquatic organisms is essential to evaluate effects of many environmental challenges like effects of hydro-power regulation, where stranding may occur under hydropeaking (rapid dewatering of shallow river ... -
Desnity dependent habitat use of Atlantic salmon, Salmo salar L.- stranding in hydropower rivers
Bentsen, Vidar Johan (Master thesis, 2011)An experiment was performed in four artificial stream channels during summer and autumn to investigate the effects of biotic and abiotic factors on habitat choice of juvenile Atlantic salmon (Salmo salar). To investigate ... -
Divergence in Thermal Reaction Norms of Life-History Traits Among Populations of Daphnia magna
Bartuseviciute, Vitalija (Master thesis, 2018)Patterns of phenotypic and genetic variance in thermal reaction norms allow predicting evolutionary response for a population. The ability of phenotypic traits to respond to selection depends on their genetic variance, and ... -
Ecological modeling of metabolic rates predicts diverging optima across food abundances
Einum, Sigurd (Journal article; Peer reviewed, 2014)Genetically based variation in metabolic rates of resting animals (RMR) suggests a potential role for evolutionary adaptations, but mechanistic models yielding evolutionary predictions are lacking. Here I utilize the ... -
Effects of intra- and interspecific competition and hydropeaking on growth of juvenile Atlantic salmon (Salmo salar)
Puffer, Michael; Berg, Ole Kristian; Huusko, Ari; Vehanen, Teppo; Einum, Sigurd (Journal article, 2017)The effects of hydropeaking and intra- and interspecific competition on the growth performance (growth in length, mass and lipid content) of juvenile Atlantic salmon Salmo salar and brown trout Salmo trutta were studied ... -
Energetic Consequences of Stranding of Juvenile Atlantic Salmon (Salmo salar L.)
Puffer, Michael; Berg, Ole Kristian; Einum, Sigurd; Saltveit, Svein Jakob; Forseth, Torbjørn (Journal article, 2017)An effect of hydropower and hydropeaking regulation in rivers is stranding of fish. Those fishes that survive stranding may experience stranding as a stressful situation. In four experimental stranding experiments (each ... -
Genetic and environmental effects on the scaling of metabolic rate with body size
Fossen, Erlend Ignacio Fleck; Pelabon, Christophe; Einum, Sigurd (Peer reviewed; Journal article, 2019)Metabolic rate (MR) often scales with body mass (BM) following a power function of the form MR=aBMb, where log(a) is the allometric intercept and b is the allometric exponent (i.e. slope on a log–log scale). The variational ... -
Genetic Variation in Metabolic Rate and Correlations with Other Energy Budget Components and Life History in Daphnia magna
Einum, Sigurd; Fossen, Erlend Ignacio Fleck; Parry, Victor; Pelabon, Christophe (Peer reviewed; Journal article, 2019)Much is known about the genetic variance in certain components of metabolism, most notably resting and maximum metabolic rate. This is in stark contrast to the lack of information on genetic variance in the metabolic rate ... -
Gross Growth Efficiency of Daphnia magna:Genetic Variance and Effects of Temperature
Parry, Victor (Master thesis, 2017)Gross Growth Efficiency (GGE) is defined as the ratio between Somatic Growth Rate (SGR) and food consumption, and hence represents the quantity of food eaten that is converted to body mass. SGR correlates with intrinsic ... -
Growth and Movement in Brown Trout (Salmo trutta) in two Norwegian Rivers
Skjellevik, Stine Marie (Master thesis, 2012)In the present study, using stream-dwelling brown trout (Salmo trutta) as a model species, movement through the summer and autumn in two large Norwegian rivers, River Glomma and River Gudbrandsdalslågen, was observed. ... -
Historical abundance and spatial distributions of spawners determine juvenile habitat accessibility in salmon: implications for population dynamics and management targets
Finstad, Anders Gravbrøt; Sættem, Leif Magnus; Einum, Sigurd (Journal article; Peer reviewed, 2013)Spatial distribution of spawning may have important ramifications for population dynamics in species where early life stages suffer from low mobility and high density-dependent mortality. Here, we use time series of spatial ... -
How to quantify thermal acclimation capacity?
Einum, Sigurd; Ratikainen, Irja Ida; Wright, Jonathan; Pelabon, Christophe; Bech, Claus; Jutfelt, Fredrik; Stawski, Clare; Burton, Tim (Peer reviewed; Journal article, 2019)The capacity of organisms to acclimate will influence their ability to cope with ongoing global changes in thermal regimes. Here we highlight methodological issues associated with recent attempts to quantify variation in ... -
Impact of whitefish on Cladocera communities
Eid, Simon Ormestad (Master thesis, 2019)Introduserte arter har blitt vist å ha effekter på lokal populasjoner både i eksperimenter og i studier av økosystemer. For å kunne ivareta biodiversitet og økosystemtjenester er økt forståelse av menneskelig påvirkning ... -
Interactions between local population density and limited habitat resources determine movements of juvenile Atlantic salmon
Teichert, Maxim; Foldvik, Anders; Einum, Sigurd; Finstad, Anders Gravbrøt; Forseth, Torbjørn; Ugedal, Ola (Journal article; Peer reviewed, 2017)Competition for limited resources and the resulting density-dependent processes are key factors in driving stream salmonid population dynamics. Here we test for the combined effects of density and shelter availability on ...