More new ARCTOS PhDs – Raphaëlle Descôteaux and Apollo Lizano

Raphaëlle successfully defended her PhD on October 5th at UiT in Tromsø. The title of her thesis is: ‘Meroplankton on Arctic inflow shelves: Diversity, seasonality and origins of benthic invertebrate larvae on the Barents and Chukchi shelves‘ and can be downloaded HERE.

Her supervisors have been: Bodil Bluhm (UiT), Paul Renaud (Akvaplan-niva), Kim Præbel (UiT), Randi Ingvaldsen (IMR), and Jørgen Berge (UiT).

Raphaëlle’s thesis consists of three articles:

  1. Descôteaux, R., Ershova, E., Wangensteen, O.S., Præbel, K., Renaud, P.E., Cottier, F. & Bluhm, B.A. (2021). Meroplankton diversity, seasonality and life-history traits across the Barents Sea Polar Front revealed by high-throughput DNA barcoding. Frontiers in Marine Science, 8, 677732.
  2. Descôteaux, R., Huserbråten, M., Jørgensen, L.L., Renaud, P.E., Ingvaldsen, R.B., Ershova, E.A. & Bluhm, B.A. Origin of marine invertebrate larvae on an Arctic inflow shelf. In press in Marine Ecology Progress Series
  3. Ershova, E.A., Descôteaux, R., Wangensteen, O.S., Iken, K., Hopcroft, R.R., Smoot, C., Grebmeier, J.M. & Bluhm, B.A. (2019). Diversity and distribution of meroplanktonic larvae in the Pacific Arctic and connectivity with adult benthic invertebrate communities. Frontiers in Marine Science, 6, 490.

Photo top: From left to right: Penelope Lindeque (Plymouth Marine Laboratory, UK) Paul Renaud (Akvaplan-niva, Tromsø), Raphaëlle Descôteaux (UiT, Tromsø), Bodil Bluhm (UiT, Tromsø), Sünnje Basedow (UiT, Tromsø), Paul Snelgrove (Memorial University of Newfoundland, Canada). Photo: Marit Reigstad/UiT

From left to right: Mette Sørensen (Nord University), Daniel Mayor (National Oceanography Center, Southampton, UK), Marvin Choquet (Uppsala University, Sweden), Apollo Lizano (Nord University, Bodø), Galice Hoarau (Nord University, Bodø), Vigdis Tverberg (Nord University, Bodø), Vittoria Roncalli (Stazione Zoologica Anton Dohrn, Italy), Jarle Sørensen (Nord University). Photo: Jeanett Stegen/Nord University

Apollo successfully defended his thesis on October 7th at Nord University in Bodø. The title of his thesis is: ‘Examining challenges in species-level taxonomy among Calanus copepods in the Northern seas using genome and transcriptome data‘ and is available upon request to Jeanett Stegen (

His supervisors have been Galice Hoarau (Nord University, Bodø) and Marvin Choquet (Uppsala University, Sweden).

Summary of Apollo’s thesis:

The copepod genus Calanus or “Raudåte” by Norwegian name is an ecologically important marine species in the Northern Seas (North Atlantic, Arctic, and Northern Pacific). Calanus species play a key role in ene​rgy transfer in marine food webs, both as primary consumers and as prey for fish, seabirds, and other marine predators. Commercially, they have been a great source of Omega-3 fatty acid. 

Despite their ecological and commercial importance, species-level taxonomy in the genus Calanus remains challenging because of their identical morphology, overlapping distribution, huge genome sizes, and limited genomic and transcriptomics resources. Species-level identification in the genus Calanus is very important for their proper conservation and management. 

The current fisheries regulations in Norway only focuses on a single species, C. finmarchicus. However, recent genetic analyses using few molecular markers have shown overlapping distribution for at least several species across the Northern Seas, including the Norwegian fjords. 

This thesis addressed some of these specieslevel taxonomy problems present in the genus Calanus using genomics and transcriptomics approaches, which aides in the proper understanding of their ecology and evolution. Results of these studies may also have implications in the current fisheries regulations implemented in the country.​

Congratulation to both Raphaëlle and Apollo and all the best for their future!