Jahn Throndsen

• Edvardsen, Bente; Eikrem, Wenche; Throndsen, Jahn; Sáez, Alberto; Probert, Ian & Medlin, Linda K. (2011). Ribosomal DNA phylogenies and a morphological revision provide the basis for a revised taxonomy of Prymnesiales (Haptophyta). European journal of phycology. ISSN 0967-0262. 46(3), p. 202–228. doi: 10.1080/09670262.2011.594095. Show summary

  Nucleotide sequences of the nuclear-encoded small subunit (18S rDNA) and partial large subunit (28S rDNA) ribosomal DNA were determined in 30 different species of the haptophyte genera Prymnesium, Chrysocampanula, Chrysochromulina, Imantonia and Platychrysis, all belonging to the order Prymnesiales. Phylogenies based on these and other available haptophyte 18S, 28S and plastid 16S rDNA sequences were reconstructed, and compared with available morphological and ultrastructural data. The rDNA phylogenies indicate that the genus Chrysochromulina is paraphyletic and is divided into two major clades. This is supported by ultrastructural and morphological data. There is a major split between Chrysochromulina species with a saddle-shaped cell form (clade B2) and the remaining species in the genus (clade B1). Clade B2 includes the type species C. parva and taxa belonging to this clade thus retain the name Chrysochromulina. The non-saddle-shaped Chrysochromulina species analysed are closely related to Hyalolithus, Prymnesium and Platychrysis species. Imantonia species are sister taxa to these species within clade B1. An amendment to the classification of the order Prymnesiales and the genera Prymnesium, Platychrysis and Chrysochromulina is proposed with one new and one emended family (Chrysochromulinaceae and Prymnesiaceae, respectively), two new genera (Haptolina and Pseudohaptolina), and one new species (Pseudohaptolina arctica). We suggest a revision of the taxonomy of the Prymnesiales that is in accordance with available molecular evidence and supported by morphological data.

• Eikrem, Wenche; Edvardsen, Bente & Throndsen, Jahn (2009). Research note: Renaming Verrucophora farcimen Eikrem, Edvardsen et Throndsen. Phycological Research. ISSN 1322-0829. 57(3), p. 170–170. doi: 10.1111/j.1440-1835.2009.00535.x.
• Edvardsen, B; Eikrem, W; Shalchian-Tabrizi, K; Riisberg, I; Johnsen, Geir & Naustvoll, L [Show all 7 contributors for this article] (2007). Verrucophora farcimen gen. et sp nov (Dictyochophyceae, Heterokonta) - A bloom-forming ichthyotoxic flagellate from the Skagerrak, Norway. Journal of Phycology. ISSN 0022-3646. 43, p. 1054–1070. doi: 10.1111/j.1529-8817.2007.00390.x.
• Shalchian-Tabrizi, Kamran; Eikrem, Wenche; Klaveness, Dag; Vaulot, Daniel; Minge, Marianne Aastebøl & LeGall, F [Show all 12 contributors for this article] (2006). Telonemia, a new protist phylum with affinity to chromist lineages. Proceedings of the Royal Society of London. Biological Sciences. ISSN 0962-8452. 273, p. 1833–1842. doi: 10.1098/rspb.2006.3515.
• Eikrem, Wenche & Throndsen, Jahn (2004). Florenciella parvula gen. et sp. nov. (Dictyochophyceae, Heterokontophyta), a small flagellate isolated from the English Channel. Phycologia. ISSN 0031-8884. 43(6), p. 658–668.
• Throndsen, Jahn & Andersen, P (2003). Estimating cell numbers. In Hallegraeff, G.M.; Anderson, D.M. & Cembella, A.D. (Ed.), Manual on Harmful Marine Microalgae. UNESCO Publishing. ISSN 92-3-103871-0. p. 99–129.
• Backe-Hansen, Pia & Throndsen, Jahn (2002). Occurrence of pico- and smaller nanoplanktonic flagellates in the inner Oslofjord, eastern Norway, during the breeding season of the blue mussel (Mytilus edulis L.). Sarsia. ISSN 0036-4827.
• Backe-Hansen, Pia & Throndsen, Jahn (2002). Pico- and nanoplankton from the inner Oslofjord, eastern Norway, including description of two new species of Luffisphaera (incerta sedis). Sarsia. ISSN 0036-4827. 87, p. 55–64.
• Eikrem, Wenche & Throndsen, Jahn (1999). The morphology of Chrysochromulina rotalis sp. nov. (Prymnesiophyceae, Haptophyta), isolated from the Skagerrak. Sarsia. ISSN 0036-4827. 84(5/6). Show summary

  Chrysochromulina rotalis sp. nov. was isolated from surface water in the Skagerrak (58 11'N, 09 06'E) using the serial dilution culture method. The cells are saddle shaped with the appendages inserted subapically on the ventral side of the cell. The coiling haptonema measures 2-4 times the length of the flagella when extended. The cells contain two golden brown chloroplasts. The periplast is covered by two types of scale with dimorphic scale faces. The scales constituting the outer layer bear a short spine supported by four struts, the inner layer scales lack protrusions.

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• Throndsen, Jahn & Hasle, Grethe Rytter (2003). Norsk kystplanktonflora. Almater forlag A/S. ISBN 82-7858-037-5. 341 p.
• Billard, Chantal; Booth, Beatrice; Kristiansen, Jørgen; Moestrup, Øjvind; Preisig, Hans R. & Throndsen, Jahn (2001). Encyclopedia of Chrysophyte Genera. J.Cramer, Berlin. ISBN 3-443-60037-9. 110. 260 p.
• Throndsen, Jahn & Eikrem, Wenche (2001). Marine mikroalger i farger. Almater Forlag AS. ISBN 82-7858-030-8. 188 p. Show summary

  Innføring i kystvannets planteplankton illustrert med strektegninger, fotografier, mikrofotografier og noen elektronmikrografier. Mer enn 60 encellede algeslekter fra planktonet er presentert, enkelte med flere arter.

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• Eikrem, Wenche; Medlin, Linda K.; Henderiks, Jorijntje; Rokitta, Sebastian; Rost, Björn & Throndsen, Jahn [Show all 8 contributors for this article] (2017). Haptophyta. In Archibald, John M.; Simpson, Alastair G B & Slamovits, Claudio H (Ed.), Handbook of the Protists. Springer Publishing Company. ISSN 978-3-319-28148-3. p. 1–61. doi: 10.1007/978-3-319-32669-6_38-1. Show summary

  Haptophyta are predominantly planktonic and phototrophic organisms that have their main distribution in marine environments worldwide. They are a major component of the microbial ecosystem, some form massive blooms and some are toxic. Haptophytes are significant players in the global carbonate cycle through photosynthesis and calcification. They are characterized by the haptonema, a third appendage used for attachment and food handling, two similar flagella, two golden-brown chloroplasts, and organic body scales that serve in species identification. Coccolithophores have calcified scales termed coccoliths. Phylogenetically Haptophyta form a well-defined group and are divided into two classes Pavlovophyceae and Coccolithophyceae (Prymnesiophyceae). Currently, about 330 species are described. Environmental DNA sequencing shows high haptophyte diversity in the marine pico- and nanoplankton, of which many likely represent novel species and lineages. Haptophyte diversity is believed to have peaked in the past and their presence is documented in the fossil record back to the Triassic, approximately 225 million years ago. Some biomolecules of haptophyte origin are extraordinarily resistant to decay and are thus used by geologists as sedimentary proxies of past climatic conditions.

• Silva, Paul C.; Throndsen, Jahn & Eikrem, Wenche (2007). Revisiting the nomenclature of haptophytes. Phycologia. ISSN 0031-8884. 46, p. 471–475. doi: 10.2216/07-22.1.
• Throndsen, Jahn & Eikrem, Wenche (2007). Mikroflagellater i norske sandstrender. Naturen. ISSN 0028-0887. 131(5), p. 202–208.
• Eikrem, Wenche; Throndsen, Jahn; Edvardsen, Bente & Naustvoll, Lars (2006). Morphology and ultrastructure of Chattonella aff. verruculosa (Heterokontophyta).
• Edvardsen, Bente; Eikrem, Wenche; Shalchian-Tabrizi, Kamran; Riisberg, Ingvild; Johnsen, Geir & Naustvoll, Lars [Show all 7 contributors for this article] (2005). Phylogeny of a new ichthyotoxic dictyochophyte forming blooms in the North Sea.
• Edvardsen, Bente; Eikrem, Wenche; Johnsen, Geir; Shalchian-Tabrizi, Kamran; Riisberg, Ingvild & Naustvoll, Lars [Show all 7 contributors for this article] (2004). Phylogeny of a new ichthyotoxic dictyochophyte forming blooms in the Skagerrak. Show summary

  Since 1998 a heterokont flagellate, initially identified as Chattonella aff. verruculosa, has formed recurrent extensive blooms in the North Sea and Skagerrak causing mortality in farmed salmon. Strains were isolated from a 2001 bloom off the south coast of Norway and compared with a �Chattonella verruculosa� strain from Japan. The cells in Norwegian strains are oblong to round with numerous chloroplasts and mycocyst-like organelles. The complete SSU and partial LSU rRNA gene sequences from strains from Norway and Japan were similar, but not identical, and differed clearly from rDNA sequences of other Raphidophytes. Phylogenetic trees were constructed and their relationships to other heterokontophytes determined. C. aff. verruculosa and the Japanese �C. verruculosa� appeared in a clade with members of Dictyochophyceae. Ultrastructure (e.g. the structure of flagella and flagellar apparatus, position of nucleus), morphology and pigment data (chlorophylls a, c1, c2, c3, fucoxanthin, diadinoxanthin and 19�butanoyloxyfucoxanthin) support this affinity. A new name and classification will be proposed.

• Throndsen, Jahn & Edvardsen, Bente (2003). Eystein Paasche: 70 years. Phycologia. ISSN 0031-8884. 42(1), p. 3–6.
• Throndsen, Jahn (2003). Phytoplankton of Norwegian Coastal Waters. Almater Forlag AS. ISSN 82-7858-037-5. Show summary

  Flora for planteplankton, kraveflagellater og tintinnider i norske kystfarvann, nå oversatt til engelsk. Omfatter arter fra kystvannet og nærliggende havområder.

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