Blar i Bergen Open Research Archive på forfatter "Nilsen, Tom Ole"
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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 ... -
Atlantic salmon post-smolts adapted for a longer time to seawater develop an effective humoral and cellular immune response against Salmonid alphavirus
Nuñez-Ortiz, Noelia; Moore, Lindsey; Jarungsriapisit, Jiraporn; Nilsen, Tom Ole; Stefansson, Sigurd Olav; Morton, Hugh Craig; Taranger, Geir Lasse; Secombes, Christopher J.; Patel, Sonal (Peer reviewed; Journal article, 2018-11)Salmonid alphavirus (SAV) causes pancreas disease (PD) in Atlantic salmon (Salmo salar L.) and disease outbreaks are mainly detected after seawater transfer. The influence of the smoltification process on the immune ... -
Changes in circulating insulin-like growth factor-1 and its binding proteins in yearling rainbow trout during spring under natural and manipulated photoperiods and their relationships with gill Na+, K+-ATPase and body size
Cui, Wenda; Takahashi, Eisuke; Morro, Bernat; Vigo, Pablo Balseiro; Albalat, Amaya; Pinto Pedrosa, Cindy; Mackenzie, Simon A.; Nilsen, Tom Ole; Sveier, Harald; Ebbesson, Lars O.E.; Handeland, Sigurd Olav; Shimizu, Munetaka (Journal article; Peer reviewed, 2022)Smoltification in salmonids occurs during spring in response to increasing photoperiod to prepare for marine life. Smoltification is associated with increased hypo-osmoregulatory ability and enhanced growth potential, ... -
Comparison of anadromous and landlocked Atlantic salmon genomes reveals signatures of parallel and relaxed selection across the Northern Hemisphere
Kjærner-Semb, Erik Nordtorp; Edvardsen, Rolf Brudvik; Ayllon, Fernando; Vogelsang, Petra; Furmanek, Tomasz; Rubin, Carl-Johan; Veselov, Alexey E.; Nilsen, Tom Ole; McCormick, Stephen D.; Primmer, Craig R.; Wargelius, Anna (Journal article; Peer reviewed, 2020)Most Atlantic salmon (Salmo salar L.) populations follow an anadromous life cycle, spending early life in freshwater, migrating to the sea for feeding, and returning to rivers to spawn. At the end of the last ice age ~10,000 ... -
Effects of cortisol on the intestinal mucosal immune response during cohabitant challenge with IPNV in Atlantic salmon (Salmo salar)
Niklasson, Lars; Sundh, Henrik; Olsen, Rolf Erik; Jutfelt, Fredrik; Skjødt, Karsten; Nilsen, Tom Ole; Sundell, Kristina (Peer reviewed; Journal article, 2014-05-08)Infectious pancreatic necrosis virus (IPNV) causes high incidence of disease in salmonids during the first period after SW transfer. During this period as well as during periods of stress, cortisol levels increase and ... -
Evaluation of potential reference genes in real-time RT-PCR studies of Atlantic salmon
Olsvik, Pål A.; Lie, Kai Kristoffer; Olderbakk Jordal, Anne-Lise; Nilsen, Tom Ole; Hordvik, Ivar (Peer reviewed; Journal article, 2005)Background: Salmonid fishes are among the most widely studied model fish species but reports on systematic evaluation of reference genes in qRT-PCR studies is lacking. Results: The stability of six potential reference genes ... -
Exposure to cold temperatures differentially modulates neural plasticity and stress responses in post-smolt Atlantic salmon (Salmo salar)
Tang, Patrik Anthony; Stefansson, Sigurd Olav; Nilsen, Tom Ole; Gharbi, Naouel; Lai, Floriana; Tronci, Valentina; Vigo, Pablo Balseiro; Marnix, M.; Ebbesson, Lars O.E. (Journal article; Peer reviewed, 2022)The transfer success of farmed post-smolt Atlantic salmon (Salmo salar) to sea-cages rely on neural adaptions to promote stress resilience. As low temperatures impact physiology, this suggests that off-season transfer to ... -
Expression and localization of the aryl hydrocarbon receptors and cytochrome P450 1A during early development of Atlantic cod (Gadus morhua)
Aranguren Abadía, Libe; Donald, Carey; Eilertsen, Mariann; Gharbi, Naouel; Tronci, Valentina; Sørhus, Elin; Mayer, Philipp; Nilsen, Tom Ole; Meier, Sonnich; Goksøyr, Anders; Karlsen, Odd Andre (Journal article; Peer reviewed, 2020)The aryl hydrocarbon receptor (Ahr) is a ligand-activated transcription factor that mediates the toxicity of dioxins and dioxin-like compounds (DLCs) in vertebrates. Two clades of the Ahr family exist in teleosts (Ahr1 and ... -
Hypothalamic agrp and pomc mRNA Responses to Gastrointestinal Fullness and Fasting in Atlantic Salmon (Salmo salar, L.)
Kalananthan, Tharmini; Murashita, Koji; Rønnestad, Ivar; Ishigaki, Mitsumasa; Takahashi, Kota; Silva, Marta Sofia; Wakabayashi, Yuki; Lai, Floriana; Shimizu, Munetaka; Nilsen, Tom Ole; Martinez, Enrique Pino; Gomes, Ana S. (Journal article; Peer reviewed, 2020-02-11)The orexigenic agouti-related protein (AgRP) and the anorexigenic pro-opiomelanocortin (POMC) are crucial players in the control of feed intake in vertebrates, yet their role in teleosts has not been fully established. ... -
Impact of fish density and specific water flow on skin properties in Atlantic salmon (Salmo salar L.) post-smolts
Sveen, Lene Rydal; Timmerhaus, Gerrit; Torgersen, Jacob Seilø; Ytteborg, Elisabeth; Jørgensen, Sven Martin; Handeland, Sigurd Olav; Stefansson, Sigurd Olav; Nilsen, Tom Ole; Calabrese, Sara; Ebbesson, Lars O.E.; Terjesen, Bendik Fyhn; Takle, Harald Rune (Peer reviewed; Journal article, 2016)Prolonged production of Atlantic salmon (Salmo salar) post-smolts in closed-containment systems has prompted research into biological requirements under higher production intensities. This study examined the effect of fish ... -
Increased Thermal Challenges Differentially Modulate Neural Plasticity and Stress Responses in Post-Smolt Atlantic Salmon (Salmo salar)
Tang, Patrik Anthony; Gharbi, Naouel; Nilsen, Tom Ole; Gorissen, M.; Stefansson, Sigurd Olav; Ebbesson, Lars O.E. (Journal article; Peer reviewed, 2022)The successful transfer of farmed post-smolt Atlantic salmon (Salmo salar) depends on proper stress responses and cognitive functions during the early seawater (SW) phase. However, with increasing summer oceanic temperatures, ... -
Ion transporters and osmoregulation in the kidney of teleost fishes as a function of salinity
Takvam, Marius; Wood, Chris M.; Kryvi, Harald; Nilsen, Tom Ole (Journal article; Peer reviewed, 2021-04-20)Euryhaline teleosts exhibit major changes in renal function as they move between freshwater (FW) and seawater (SW) environments, thus tolerating large fluctuations in salinity. In FW, the kidney excretes large volumes of ... -
New wine in old bottles: Modification of the Na+/K+-ATPase enzyme activity assay and its application in salmonid aquaculture
Takvam, Marius; Sundell, Kristina; Sundh, Henrik; Gharbi, Naouel; Kryvi, Harald; Nilsen, Tom Ole (Journal article; Peer reviewed, 2023)The Na+, K+ ATPase (NKA) enzyme is important to generate the transmembrane ion gradient in the gills, intestine, and kidneys, hence, is vital for secondary transport of fluids and different solutes in teleosts. Gill NKA ... -
Performance and welfare of Atlantic salmon, Salmo salar L. post-smolts in recirculating aquaculture systems: Importance of salinity and water velocity
Ytrestøyl, Trine; Takle, Harald Rune; Kolarevic, Jelena; Calabrese, Sara; Timmerhaus, Gerrit; Rosseland, Bjørn Olav; Teien, Hans-Christian; Nilsen, Tom Ole; Handeland, Sigurd O; Stefansson, Sigurd; Ebbesson, Lars; Terjesen, Bendik Fyhn (Journal article; Peer reviewed, 2020)Producing a larger post‐smolt in recirculating aquaculture systems (RAS) could shorten the production time in sea cages and potentially reduce mortality. Knowledge of the biological requirements of post‐smolts in ... -
Role of the kidneys in acid-base regulation and ammonia excretion in freshwater and seawater fish: implications for nephrocalcinosis
Takvam, Marius; Wood, Chris M.; Kryvi, Harald; Nilsen, Tom Ole (Journal article; Peer reviewed, 2023)Maintaining normal pH levels in the body fluids is essential for homeostasis and represents one of the most tightly regulated physiological processes among vertebrates. Fish are generally ammoniotelic and inhabit diverse ... -
Statistical modelling of voluntary feed intake in individual Atlantic salmon (Salmo salar L.)
Da Silva Gomes, Ana Cristina; Zimmermann, Fabian; Hevrøy, Ernst Morten; Søyland, Marcus; Hansen, Tom; Nilsen, Tom Ole; Rønnestad, Ivar (Journal article, 2023)Precision feeding aims to provide the correct amount of feed to farmed animals for optimal growth and performance and to avoid feed waste. However, knowledge underlying the meal-to-meal variability in voluntary feed intake ... -
Stocking density limits for post-smolt Atlantic salmon (Salmo salar L.) emphasis on production performance and welfare
Calabrese, Sara; Nilsen, Tom Ole; Kolarevic, Jelena; Ebbesson, Lars O.E.; Pinto Pedrosa, Cindy; Fivelstad, Sveinung; Hosfeld, Anne-Camilla Diesen; Stefansson, Sigurd Olav; Terjesen, Bendik Fyhn; Takle, Harald Rune; Martins, Catarina I.M.; Sveier, Harald; Mathisen, Frode; Imsland, Albert Kjartanson; Handeland, Sigurd Olav (Peer reviewed; Journal article, 2017-02)For the development of commercial scale semi-closed sea systems for farming post-smolt Atlantic salmon (Salmo salar), further knowledge is required on the interaction between fish density, farming conditions and fish ... -
Sulfate homeostasis in Atlantic salmon is associated with differential regulation of salmonid-specific paralogs in gill and kidney
Takvam, Marius; Denker, Elsa; Gharbi, Naouel; Kryvi, Harald; Nilsen, Tom Ole (Journal article; Peer reviewed, 2021)Sulfate (SO2−4) regulation is challenging for euryhaline species as they deal with large fluctuations of SO2−4 during migratory transitions between freshwater (FW) and seawater (SW), while maintaining a stable plasma SO2−4 ... -
Teaching method delivery: implementation of in-class student active learning
Nilsen, Tom Ole (UPED-skrift, Working paper, 2018) -
Triploid atlantic salmon (Salmo salar L.) postsmolts accumulate prevalence more slowly than diploid salmon following bath challenge with salmonid alphavirus subtype 3
Moore, Lindsey; Nilsen, Tom Ole; Jarungsriapisit, Jiraporn; Fjelldal, Per Gunnar; Stefansson, Sigurd Olav; Taranger, Geir Lasse; Patel, Sonal (Peer reviewed; Journal article, 2017-04-12)Triploid Atlantic salmon (Salmo salar L.) may play an important role in the sustainable expansion of the Norwegian aquaculture industry. Therefore, the susceptibility of triploid salmon to common infections such as salmonid ...