Blar i Bergen Open Research Archive 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 (Journal article; Peer reviewed, 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 ... -
Fast water currents reduce production performance of post-smolt Atlantic salmon Salmo salar
Solstorm, Frida; Solstorm, David; Oppedal, Frode; Fernø, Anders; Fraser, Thomas; Olsen, Rolf Erik (Peer reviewed; Journal article, 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 ... -
A new method for regionalization of the vertebral column in salmonids based on radiographic hallmarks
Murugesan, Sankar; Kryvi, Harald; Fraser, Thomas; Philip, Antony Jesu Prabhu; Remø, Sofie C.; Hansen, Tom Johnny; Witten, Paul Eckhard; Fjelldal, Per Gunnar (Journal article; Peer reviewed, 2024)Current procedures to establish vertebral column regionalization (e.g., histology) in fish are time consuming and difficult to apply. The aim of this study was to develop a more rapid and accurate radiology-based method ... -
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 (Journal article; Peer reviewed, 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 (Journal article; Peer reviewed, 2020)Background 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 ... -
Sequence of formation and inheritance of meristic variation in the post-cranial axial skeleton of Atlantic salmon (Salmo salar)
Philip, Antony Jesu Prabhu; Fraser, Thomas; Nordvik, Kari; Remø, Sofie C.; Hansen, Tom Johnny; Witten, Paul Eckhard; Kryvi, Harald; Fjelldal, Per Gunnar (Journal article; Peer reviewed, 2025)Atlantic salmon is an important aquaculture species that has fascinated naturalists for centuries, resulting in its biology being widely characterized. Certain details about the early development and the inheritance of ... -
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 (Journal article; Peer reviewed, 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 ... -
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 (Journal article; Peer reviewed, 2022)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 ... -
Vgll3 regulates the timing of puberty in farmed Atlantic salmon, but it does not explain family discordance in male maturation following different smolt production regimes
Fraser, Thomas; Tjølsen, Aslak; Madaro, Angelico; Hansen, Tom Johnny; Fjelldal, Per Gunnar (Journal article; Peer reviewed, 2024)Atlantic salmon (Salmo salar) farming is moving towards extended periods of land-based production to minimise the time at sea, but this increases the risk of unwanted male sexual maturation. As the timing of puberty is ...