My main research interest is osmoregulation and acid-base regulation in fish. My professional background is in aquaculture biology and fish physiology where I have extensive knowledge within smolt development and production protocols for salmonids such as Atlantic salmon. My main methods include bioinformatic analysis (both at gene and protein level), enzyme activity assays, gene expression, plasma/serum/urine analysis and catheterization techniques. I also have experience with immunohistochemistry, western blott and cloning.

My PhD thesis focuses on describing and mapping ion transporters in the kidney of Atlantic salmon to better understand the osmoregulatory role of the kidney, which currently is unknown in this species. The goal is to better understand kidney role and function under different environmental conditions and during critical developmental stages of their life cycle. The knowledge gained here will be important to better understand how the kidney is affected in the intensive production protocols currently used in the Norwegian salmon industry. This is especially important due to the reoccurring issues with regulative disorders such as nephrocalsinosis and hemoragic smolt syndrom (HSS) which lead to severe salt precipitation and bleedings in the kidney of salmonids.

Academic literature review

• Marius Takvam; Chris M. Wood; Harald Kryvi et al. (2021). Ion transporters and osmoregulation in the kidney of teleost fishes as a function of salinity. (external link)
• Marius Takvam; Chris M. Wood; Harald Kryvi et al. (2023). Role of the kidneys in acid-base regulation and ammonia excretion in freshwater and seawater fish: implications for nephrocalcinosis. (external link)
• Marius Takvam; Kristina Sundell; Henrik Sundh et al. (2023). New wine in old bottles: Modification of the Na+/K+-ATPase enzyme activity assay and its application in salmonid aquaculture. (external link)

Lecture

• Marius Takvam (2023). Nyrefunksjon i laksefisk - biomarkører for bruk i settefiskfasen. (external link)
• Marius Takvam (2023). Smolt Development and kidney function. (external link)
• Marius Takvam; Neda Gilannejad; Pradeep Lal et al. (2023). Effects of different photoperiod salinity and smolt size on smolt physiology in recirculating aquaculture systems. (external link)
• Marius Takvam (2023). Nyrefunksjon i laksefisk - biomarkører for bruk i settefiskfasen. (external link)
• Marius Takvam (2023). Smoltkvalitet og ny metodikk for evaluering av sjøvannstilpasning. (external link)
• Patrik Anthony Tang; Neda Gilannejad; Marius Nilsen et al. (2024). Effect of different inclusion rates of yeast Candida utilis as protein source in hybrid African catfish Clarias gariepinus x Heterobranchus longifilis stress response and lipid metabolism. (external link)
• Marius Takvam; Kristina Sundell; Henrik Sundh et al. (2023). Modifikasjoner av Na+, K+ - ATPase enzymaktivitets protokollen og bruksområder i moderne lakseoppdrett. (external link)
• Marius Takvam (2023). Fiskehelse under stort press i norsk oppdrettsnæring - mer målrettet forskning kreves for å løse de største utfordringene. (external link)
• Marius Takvam; Elsa Denker; Naouel Gharbi et al. (2023). Differential regulation of the magnesium transporter families Slc41, Cnnm and Trpm6-7 in the kidney are associated with adaption to seawater in Atlantic salmon (Salmo salar). (external link)

Research report

• Trine Ytrestøyl; Kirsti Hjelde; Pradeep Lal et al. (2023). Betydning av tidspunkt og lengde av vintersignal i RAS for prestasjon i sjø ved utsett av stor smolt. (external link)
• Pradeep Lal; Antonie Oosterkamp; Mette Espedal Brynildsrud et al. (2024). PigghåFRI – Hvordan unngå problemer med pigghå?. (external link)

Academic article

• Alf Seljenes Dalum; Marta Alarcon; Páll Gretarsson et al. (2025). Characterisation of Urocystolithiasis in Farmed Atlantic Salmon (Salmo salar L.): Histopathological Features and Pathophysiological Considerations. (external link)
• Marius Takvam; Elsa Denker; Naouel Gharbi et al. (2024). Differential regulation of magnesium transporters Slc41, Cnnm and Trpm6-7 in the kidney of salmonids may represent evolutionary adaptations to high salinity environments. (external link)
• Marius Takvam; Elsa Denker; Naouel Gharbi et al. (2021). Sulfate homeostasis in Atlantic salmon is associated with differential regulation of salmonid-specific paralogs in gill and kidney. (external link)
• Cameron M. Emadi; Chris M. Wood; Marius Takvam et al. (2025). Simulating Nephrocalcinosis in a jar: An in vitro temperature-dependent model of CO₂-induced precipitation relevant to intensive aquaculture. (external link)

Conference poster

• Neda Gilannejad; Patrik Anthony Tang; Marie Bø Randulff et al. (2023). Effect of fishmeal replacement with single cell proteins Candida sp. And Nannochloropsis sp. on rainbow trout Oncorhynchus mykiss osmoregulatory and stress responses. (external link)
• Patrik Anthony Tang; Neda Gilannejad; Marius Nilsen et al. (2023). Effect of different inclusion rates of yeast Candida utilis as protein source in hybrid african catfish Clarias gariepinus x Heterobranchus longifilis, stress response and lipid metabolism. (external link)

See a complete overview of publications in Cristin.