Blar i Publikasjoner fra CRIStin på forfatter "Fraser, Thomas"
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Atlantic salmon male post-smolt maturation can be reduced by using a 3-hour scotophase when inducing smoltification
Fraser, Thomas; Hansen, Tom Johnny; Norberg, Birgitta; Nilsen, Tom Ole; Schulz, Rüdiger W.; Fjelldal, Per Gunnar (Peer reviewed; Journal article, 2023)Photoperiod regulates the occurrence of unwanted male post-smolt maturation during the production of large (>100 g) Atlantic salmon (Salmo salar) smolts. However, the optimal daylength for triggering smoltification, but ... -
Coping with a changing environment: The effects of early life stress
Vindas, Marco Antonio; Madaro, Angelico; Fraser, Thomas; Höglund, Erik; Olsen, Rolf Erik; Øverli, Øyvind; Kristiansen, Tore S (Journal article, 2016) -
Development of supermale and all-male Atlantic salmon to research the vgll3 allele - puberty link
Fjelldal, Per Gunnar; Hansen, Tom Johnny; Wargelius, Anna; Ayllon, Fernando; Glover, Kevin Alan; Schulz, Rüdiger W.; Fraser, Thomas (Peer reviewed; Journal article, 2020)Farmed Atlantic salmon are one of the most economically significant global aquaculture products. Early sexual maturation of farmed males represents a significant challenge to this industry and has been linked with the vgll3 ... -
Effects of laboratory salmon louse infection on mortality, growth, and sexual maturation in Atlantic salmon
Fjelldal, Per Gunnar; Fraser, Thomas; Hansen, Tom Johnny; Karlsen, Ørjan; Bui, Samantha (Peer reviewed; Journal article, 2022)Elevated salmon louse infection pressure generated by salmon farming represents a major threat for wild Atlantic salmon (Salmo salar). This study explored the effect of salmon lice on mortality, and body and gonad growth ... -
Environmental and Genetic (vgll3) Effects on the Prevalence of Male Maturation Phenotypes in Domesticated Atlantic Salmon
Fraser, Thomas; Hansen, Tom Johnny; Fjelldal, Per Gunnar (Peer reviewed; Journal article, 2023)Pre-harvest male maturation is problematic for Atlantic salmon (Salmo salar) farmers and is regulated by the environment and genetics (e.g., vgll3). Five families of all-male salmon parr (produced using YY males crossed ... -
Fast currents reduce production performance of post-smolt Atlantic salmon.
Solstorm, Frida; Solstorm, David; Oppedal, Frode; Fernø, Anders; Fraser, Thomas; Olsen, Rolf Erik (Journal article; Peer reviewed, 2015-09-17)In the future, an increasing number of salmon farms may be located in areas with fast water current velocity due to limited availability of more sheltered locations. However, there is little information as to how fast ... -
Is it advantageous for Atlantic salmon to be triploid at lower temperatures?
Riseth, Erling; Fraser, Thomas; Sambraus, Florian; Stien, Lars Helge; Hvas, Malthe (Peer reviewed; Journal article, 2020)Marine organisms living at low temperatures tend to have larger genomes and larger cells which suggest that these traits can be beneficial in colder environments. In fish, triploidy (three complete sets of chromosomes) can ... -
Long term effects of smolt production strategy and early seawater phase rearing environment on mortality, growth, sexual maturation, and vertebra deformities in farmed Atlantic salmon (Salmo salar L.)
Myklatun, Lars Eirik; Fraser, Thomas; Fjelldal, Per Gunnar; Pedersen, Audun Østby; Hansen, Tom Johnny (Peer reviewed; Journal article, 2023)The life history of Atlantic salmon is plastic and determined by factors such as daylength and temperature. In aquaculture, artificial long days during smolt production maximize growth and allows for early sea-transfer, ... -
No environmental effect on vaccine-induced reduced growth in Atlantic salmon Salmo salar smolts
Fraser, Thomas; Fjelldal, Per Gunnar; Sommerset, Ingunn; Søfteland, Tina; Høstmark, Ole; Powell, Mark; Heen, Vegar; Hansen, Tom Johnny (Peer reviewed; Journal article, 2020)Oil-adjuvanted vaccines reduce long-term growth in farmed Atlantic salmon Salmo salar, possibly via an increase in metabolic rate due to the energetic demands of the immune system. We tested this hypothesis by comparing ... -
Production and verification of the first Atlantic salmon (Salmo salar L.) clonal lines
Hansen, Tom Johnny; Penman, David J.; Glover, Kevin; Fraser, Thomas; Vågseth, Tone; Thorsen, Anders; Sørvik, Anne Grete Eide; Fjelldal, Per Gunnar (Peer reviewed; Journal article, 2020)In several fish species homozygous and heterozygous clonal lines have been produced using gynogenetic and androgenetic techniques. These lines are standardized and can be reproduced over generations. In rainbow trout such ... -
Red and melanized focal changes in white skeletal muscle in Atlantic salmon (Salmo salar): Comparative analysis of farmed, wild and hybrid fish reared under identical conditions
Brimsholm, Malin Helen; Fjelldal, Per Gunnar; Hansen, Tom Johnny; Fraser, Thomas; Solberg, Monica Favnebøe; Glover, Kevin Alan; Koppang, Erling Olaf; Bjørgen, Håvard (Peer reviewed; Journal article, 2023)Selective breeding plays a vital role in the production of farmed Atlantic salmon and has shown success in many aspects. Still, challenges related to fish health and welfare continue to result in significant economic losses. ... -
Skeletal deformities in wild and farmed cleaner fish species used in Atlantic salmon Salmo salar aquaculture
Fjelldal, Per Gunnar; Madaro, Angelico; Hvas, Malthe; Stien, Lars Helge; Oppedal, Frode; Fraser, Thomas (Peer reviewed; Journal article, 2020)As a first attempt to assess bone health in cleaner fish production, wild and cultured ballan wrasse Labrus bergylta and lumpfish Cyclopterus lumpus were examined by radiology. In C. lumpus, wild fish (57%) had more vertebra ... -
Triploid Atlantic salmon and triploid Atlantic salmon × brown trout hybrids have better freshwater and early seawater growth than diploid counterparts
Fraser, Thomas; Lerøy, Hilde; Hansen, Tom Johnny; Skjæraasen, Jon Egil; Tronci, Valentina; Pinto Pedrosa, Cindy; Fjelldal, Per Gunnar; Nilsen, Tom Ole (Peer reviewed; Journal article, 2021)The use of reproductively sterile triploid salmonids would enhance the environmental sustainability of the aquaculture industry by preventing genetic exchange between escapees and wild conspecifics. To this end, we assessed ... -
Triploid Atlantic salmon Salmo salar have a higher dietary phosphorus requirement for bone mineralization during early development
Sambraus, Florian; Hansen, Tom Johnny; Daae, Britt Sværen; Thorsen, Anders; Sandvik, Roar; Stien, Lars Helge; Fraser, Thomas; Fjelldal, Per Gunnar (Peer reviewed; Journal article, 2020)The effect of a dietary phosphorus regime in freshwater on vertebra bone mineralization was assessed in diploid and triploid Atlantic salmon, Salmo salar. Fish were fed either a low phosphorus (LP) diet containing 10.5 ... -
Triploid Atlantic salmon × brown trout hybrids have similar seawater growth and welfare issues as triploid Atlantic salmon, but both were heavier at harvest than their diploid counterparts
Fraser, Thomas; Hansen, Tom Johnny; Remø, Sofie C.; Olsen, Rolf Erik; Fjelldal, Per Gunnar (Peer reviewed; Journal article, 2022)Interspecific hybridisation may improve the farm performance of sterile triploid salmonids via heterosis (i.e. hybrid vigour). We assessed growth over the final 293 days in seawater, and harvest quality, in diploid and ... -
Triploidy effects growth, life history strategies, and bone health in Arctic char (Salvelinus alpinus), but does not impact cataract incidence
Fraser, Thomas; Hansen, Tom Johnny; Remø, Sofie C.; Fjelldal, Per Gunnar (Peer reviewed; Journal article, 2021)Skeletal deformities and ocular cataracts have limited the farm performance of sterile triploid salmonids, but have not been assessed in Arctic char (Salvelinus alpinus). We repeatedly radiographed mixed-sex diploid and ... -
Triploidy leads to a mismatch of smoltification biomarkers in the gill and differences in the optimal salinity for post-smolt growth in Atlantic salmon
de Fonseka, Raneesha; Fjelldal, Per Gunnar; Sambraus, Florian; Nilsen, Tom Ole; Remø, Sofie C.; Stien, Lars Helge; Reinardy, Helena; Madaro, Angelico; Hansen, Tom Johnny; Fraser, Thomas (Peer reviewed; Journal article, 2021)Sterile triploid Atlantic salmon (Salmo salar) show inconsistent seawater grow-out, but the reason why remains unclear. The purpose of this study was to determine the salinity optima of triploid post-smolts. Diploids and ... -
Vertebral deformities in interspecific diploid and triploid salmonid hybrids
Fraser, Thomas; Hansen, Tom Johnny; Sambraus, Florian; Fjelldal, Per Gunnar (Peer reviewed; Journal article, 2020)