Diversity and biogeography of Norwegian nudibranchs (Gastropoda, Nudibranchia)

Aeolidia papillosa Foto: Torkild Bakken, NTNU Vitenskapsmuseet


Sea slugs, or nudibranchs, had not been studied at all in Norway the past 60 years, until our project was initialised in 1997. We have been studying diversity of species and their distribution in Norwegian waters.




In total about 90 species are known from Norwegian waters. Several taxonomic problems have been lined out, which is the aim to study in ongoing research. We are using DNA barcoding to map and study the nudibranch fauna, and by this contribute with data to the International Barcode of Life project.

Current projects:

  • DNA barcoding of Norwegian nudibranchs
  • Species discrimination of the Doto fragilis complex
  • Species discrimination in Flabellina
  • Onchidorididae - diversity and distribution
  • Redescription and phylogenetic position of Berghia norvegica


Head of the NH department at NTNU University Museum, and project leader, Torkild Bakken

Project Status: Active



  • Evertsen J, Bakken T. 2013. Diversity of Norwegian sea slugs (Nudibranchia): new species to Norwegian coastal waters and new data on distribution of rare species. Fauna norvegica 32: 45-52. DOI: 10.5324/fn.v32i0.1576
  • Evertsen J, Bakken T. 2005. Nudibranch diversity (Heterobranchia, Gastropoda) along the coast of Norway. Fauna norvegica 25: 1-37.
  • Evertsen J, Bakken T, Green S. 2004. Redescovery of Tenellia adspersa (Nudibranchia) from the Finnish archipelago. Sarsia 89: 362-365.
  • Evertsen J, Bakken T. 2002. Heterobranchia (Mollusca, Gastropoda) from northern Norway, with notes on ecology and distribution. Fauna norvegica 22: 15-22.