Blar i Bergen Open Research Archive på forfatter "Fjelldal, Per Gunnar"
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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 ... -
Auto-Adhesion Potential of Extraocular Aqp0 during Teleost Development
Chauvigné, Francois; Fjelldal, Per Gunnar; Cerdà, Joan; Finn, Roderick Nigel (Peer reviewed; Journal article, 2016-05-06)AQP0 water channels are the most abundant proteins expressed in the mammalian lens fiber membranes where they are essential for lens development and transparency. Unlike other aquaporin paralogs, mammalian AQP0 has a low ... -
Autosomal sdY pseudogenes explain discordances between phenotypic sex and DNA marker for sex identification in Atlantic salmon
Ayllon, Fernando; Solberg, Monica Favnebøe; Besnier, Francois; Fjelldal, Per Gunnar; Hansen, Tom Johnny; Wargelius, Anna; Edvardsen, Rolf Brudvik; Glover, Kevin (Journal article; Peer reviewed, 2020)Despite the key role that sex-determination plays in evolutionary processes, it is still poorly understood in many species. In salmonids, which are among the best studied fishes, the master sex-determining gene sexually ... -
Changes in water temperature and oxygen: the effect of triploidy on performance and metabolism in large farmed Atlantic salmon
Sambraus, Florian; Remen, Mette; Olsen, Rolf Erik; Hansen, Tom Johnny; Waagbø, Rune; Torgersen, Thomas; Lock, Erik-Jan; Imsland, Albert; Fraser, Thomas W.K.; Fjelldal, Per Gunnar (Peer reviewed; Journal article, 2018)In salmon farming, the use of sterile triploids (3N) can mitigate the problem of escapees interbreeding with wild salmon. However, triploid salmon appear less tolerant to high water temperatures and low oxygen levels ... -
Chromosome aberrations in pressureinduced triploid Atlantic salmon
Glover, Kevin; Harvey, Alison C.; Hansen, Tom Johnny; Fjelldal, Per Gunnar; Besnier, Francois; Bos, J.B.; Ayllon, Fernando; Taggart, John B.; Solberg, Monica Favnebøe (Journal article; Peer reviewed, 2020)Background Triploid organisms have three sets of chromosomes. In Atlantic salmon, hydrostatic pressure treatment of newly fertilized eggs has been extensively used to produce triploids which are functionally sterile due ... -
Cloned and outbred Atlantic salmon display equal parasite dispersion when infected with the salmon louse
Glover, Kevin; Hansen, Tom Johnny; Besnier, Francois; Solberg, Monica Favnebøe; Fjelldal, Per Gunnar; Sørvik, Anne Grete Eide; Dalvin, Sussie; Nilsen, Frank (Peer reviewed; Journal article, 2017-11)The salmon louse is an ectoparasitic copepod that infects salmonids in the marine environment. This parasite causes a major economic and biological challenge to the Atlantic salmon farming industry, and efforts to increase ... -
Dietary zinc, selenium and water temperature during early seawater phase influences the development of vertebral deformities and cataract in adult Atlantic salmon
Philip, Antony Jesu Prabhu; Fjelldal, Per Gunnar; Remø, Sofie C.; Silva, Marta Sofia; Holme, May-Helen; Lock, Erik Jan Robert; Waagbø, Rune (Journal article; Peer reviewed, 2023)The impact of dietary trace minerals (TM; zinc and selenium) and water temperature during early seawater phase on the development of vertebral deformities and cataracts in adult Atlantic salmon was studied. Two experimental ... -
The Distribution of IgT mRNA+ Cells in the Gut of the Atlantic Salmon (Salmo salar L.)
Castro, Pedro Luis; Barac, Fran; Hansen, Tom Johnny; Fjelldal, Per Gunnar; Hordvik, Ivar; Bjørgen, Håvard; Koppang, Erling Olaf (Journal article; Peer reviewed, 2023)The newly discovered IgT+ B cell is thought to play a dominant role in mucosal immunity, but limited studies have examined its distribution in fish species, hindering our understanding of its function. This study investigated ... -
Dive to survive: effects of capture depth on barotrauma and post-release survival of Atlantic cod (Gadus morhua) in recreational fisheries
Ferter, Keno; Weltersbach, Marc Simon; Humborstad, Odd Børre; Fjelldal, Per Gunnar; Sambraus, Florian; Strehlow, Harry Vincent; Vølstad, Jon Helge (Peer reviewed; Journal article, 2015-06-04)Atlantic cod (Gadus morhua) caught in recreational fisheries are commonly released, often with barotrauma after rapid decompression. Mouth-hooked, non-bleeding cod kept in a floating net pen showed mortalities ≥40% when ... -
The effect of continuous light at low temperatures on growth in Atlantic salmon reared in commercial size sea pens
Imsland, Albert; Roth, Bjørn; Fjelldal, Per Gunnar; Stefansson, Sigurd Olav; Handeland, Sigurd Olav; Mikalsen, Bjørn (Peer reviewed; Journal article, 2017-10)The aim of this study was to investigate the effect of continuous light of different duration, applied from late autumn to spring in the second year of the production cycle, on the production performance of Atlantic salmon ... -
Evolutionary drivers of kype size in atlantic salmon (salmo salar): domestication, age and genetics
Perry, William; Solberg, Monica Favnebøe; Besnier, Francois; Dyrhovden, Lise; Matre, Ivar Helge; Fjelldal, Per Gunnar; Ayllon, Fernando; Creer, Simon; Llewellyn, Martin; Taylor, Martin I.; Carvalho, Gary; Glover, Kevin (Peer reviewed; Journal article, 2019-04-17)The diversity of reproduction and associated mating patterns in Atlantic salmon (Salmo salar) has long captivated evolutionary biologists. Salmo salar exhibit strategies involving migration, bold mating behaviours and ... -
Flesh quality of Atlantic salmon smolts reared at different temperatures and photoperiods
Imsland, Albert; Roth, Bjørn; Døskeland, Inge; Fjelldal, Per Gunnar; Stefansson, Sigurd Olav; Handeland, Sigurd O; Mikalsen, Bjørn (Peer reviewed; Journal article, 2019)Possible interactive effects of temperature and photoperiod on flesh quality in Atlantic salmon post‐smolts were studied. Juvenile (initial mean weight 96.0 g ± 3.1 SEM ) Atlantic salmon were reared at six different ... -
Hatching time and alevin growth prior to the onset of exogenous feeding in farmed, wild and hybrid Norwegian Atlantic salmon
Solberg, Monica Favnebøe; Fjelldal, Per Gunnar; Nilsen, Frank; Glover, Kevin (Peer reviewed; Journal article, 2014-12-01)The onset of exogenous feeding, when juveniles emerge from the gravel, is a critical event for salmonids where early emergence and large size provide a competitive advantage in the wild. Studying 131 farmed, hybrid and ... -
Heads and tails: The notochord develops differently in the cranium and caudal fin of Atlantic Salmon (Salmo salar, L.)
Kryvi, Harald; Nordvik, Kari; Fjelldal, Per Gunnar; Eilertsen, Mariann; Helvik, Jon Vidar; Støren, Eivind Wilhelm Nagel; Long, John H. (Journal article; Peer reviewed, 2020)While it is well known that the notochord of bony fishes changes over developmental time, less is known about how it varies across different body regions. In the development of the Atlantic salmon, Salmo salar L., cranial ... -
Impact of Antioxidant Feed and Growth Manipulation on the Redox Regulation of Atlantic Salmon Smolts
Yin, Peng; Bjørnsson, Bjørn Thrandur; Fjelldal, Per Gunnar; Saito, Takaya; Remø, Sofie C.; Edvardsen, Rolf Brudvik; Hansen, Tom Johnny; Sharma, Sandeep; Olsen, Rolf Erik; Hamre, Kristin (Journal article; Peer reviewed, 2022-08-30)Accumulating evidence indicates a close relationship between oxidative stress and growth rate in fish. However, the underlying mechanisms of this relationship remain unclear. This study evaluated the combined effect of ... -
The influence of vgll3 genotypes on sea age at maturity is altered in farmed mowi strain Atlantic salmon
Ayllon, Fernando; Solberg, Monica Favnebøe; Glover, Kevin; Mohammadi, Faezeh; Kjærner-Semb, Erik Nordtorp; Fjelldal, Per Gunnar; Andersson, Eva; Hansen, Tom Johnny; Edvardsen, Rolf; Wargelius, Anna (Peer reviewed; Journal article, 2019-05-06)Background: In Atlantic salmon in the wild, age at maturity is strongly influenced by the vgll3 locus. Under farming conditions, light, temperature and feeding regimes are known significantly advance or delay age at maturity. ... -
Judging a salmon by its spots: Environmental variation is the primary determinant of spot patterns in Salmo salar
Jørgensen, Katarina Mariann; Solberg, Monica Favnebøe; Besnier, Francois; Thorsen, Anders; Fjelldal, Per Gunnar; Skaala, Øystein; Malde, Ketil; Glover, Kevin (Peer reviewed; Journal article, 2018-04-12)Background. In fish, morphological colour changes occur from variations in pigment concentrations and in the morphology, density, and distribution of chromatophores in the skin. However, the underlying mechanisms remain ... -
Mapping the pattern of essential neuroendocrine cells related to puberty and VA opsin expression provides further insight in the photoreceptive regulation of the BPG axis in Atlantic salmon (Salmo salar)
Horne, Christine; Helvik, Jon Vidar; Fleming, Mitchell Stewart; Fjelldal, Per Gunnar; Eilertsen, Mariann (Journal article; Peer reviewed, 2022)In Atlantic salmon (Salmo salar), seasonal photoperiod is shown to regulate the onset of sexual maturation, yet which brain region(s) is involved, and how light information impacts the neuroendocrine system are still not ... -
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 ... -
The notochord in Atlantic salmon (Salmo salar L.) undergoes profound morphological and mechanical changes during development
Kryvi, Harald; Rusten, Iselin; Fjelldal, Per Gunnar; Nordvik, Kari; Totland, Geir Kåre; Karlsen, Tine Veronica; Wiig, Helge; Long, John H. (Peer reviewed; Journal article, 2017-11)We present the development of the notochord of the Atlantic salmon (Salmo salar L.), from early embryo to sexually mature fish. Over the salmon's lifespan, profound morphological changes occur. Cells and gross structures ...