Radiolaria and Phaeodaria (siliceous Rhizaria) in south-western and northern Norwegian fjords during late summer 2016: dominant species and biomass in shallow-water assemblages

Takahito Ikenoue; Kjell Bjørklund; Anders K. Krabberød; Shigeto Nishino; Paul Wassmann

doi:10.33265/polar.v42.9584

Takahito Ikenoue Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan https://orcid.org/0000-0003-1693-8434
Kjell Bjørklund Natural History Museum, University of Oslo, Oslo, Norway https://orcid.org/0000-0001-5323-2065
Anders K. Krabberød Department of Biosciences, Centre for Integrative Microbial Evolution and Centre for Epigenetics Development and Evolution, University of Oslo, Oslo, Norway https://orcid.org/0000-0001-9481-8396
Shigeto Nishino Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan https://orcid.org/0000-0002-0560-241X
Paul Wassmann Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway https://orcid.org/0000-0002-6643-2792

DOI: https://doi.org/10.33265/polar.v42.9584

Keywords: zooplankton, biogeochemical cycle, climate change, biodiversity, Amphimelissa setosa, local extinction

Abstract

To determine the present-day community composition of siliceous Rhizaria (Radiolaria and Phaeodaria) in Norwegian fjords, plankton tows were conducted in south-western and northern Norwegian fjords in September 2016. The mean total abundance of radiolarians was 306 m^–3 in the Sognefjord complex, which was the southern research site, and, in the north, 945 m^–3 in Malangen and 89 m^–3 in Balsfjord, both above the Arctic Circle. Sticholonche zanclea was the most abundant radiolarian in the Sognefjord complex and Malangen, accounting for 78–100% (mean 89%) of radiolarian abundance. The mean total abundance of phaeodarians was 1554 m^–3 in the Sognefjord complex, 51 m^–3 in Malangen and 11 m^–3 in Balsfjord. Medusetta arcifera was the most abundant phaeodaria in the Sognefjord complex, accounting for >99% of phaeodarian abundance, but was absent in Malangen and Balsfjord, where Protocystis tridens accounted for >96% of phaeodarian abundance. The carbon biomass of S. zanclea and M. arcifera was 188 and 438 µg C m^–3, respectively, which is similar to and 8.6 times higher than, respectively, that of phaeodarians >1 mm in the western North Pacific, suggesting that M. arcifera contributes to organic carbon transport in the Sognefjord complex. Amphimelissa setosa (Nassellaria, Radiolaria), which was a dominant species in the study area in 1982–83, was absent in the present study in all sampled fjords. This could have been caused by the approximately 2 °C increase in water temperature that has occurred since 1990 and can be taken as evidence of a climate-change-associated local temperature rise linked to the warming of advected Atlantic Water.

Downloads

Download data is not yet available.

References

Aarseth I., Bjerkli K., Björklund K.R., Böe D., Holm J.P., Lorentzen-Styr T.J., Myhre L.A., Ugland E.S. & Thiede J. 1975. Late quaternary sediments from Korsfjorden, western Norway. Sarsia 58, 43–66, doi: 10.1080/00364827.1975.10411278.

Adl S.M., Bass D., Lane C.E., Lukeš J., Schoch C.L., Smirnov A., Agatha S., Berney C., Brown M.W., Burki F., Cárdenas P., Čepička I., Chistyakova L., Del Campo J., Dunthorn M., Edvardsen B., Eglit Y., Guillou L., Hampl V., Heiss A.A., Hoppenrath M., James T.Y., Karnkowska A., Karpov S., Kim E., Kolisko M., Kudryavtsev A., Lahr D.J.G., Lara E., Le Gall L., Lynn D.H., Mann D.G., Massana R., Mitchell E.A.D., Morrow C., Park J.S., Pawlowski J.W., Powell M.J., Richter D.J., Rueckert S., Shadwick L., Shimano S., Spiegel F.W., Torruella G., Youssef N., Zlatogursky V. & Zhang Q. 2019. Revisions to the classification, nomenclature, and diversity of eukaryotes. Journal of Eukaryotic Microbiology 66, 4–119, doi: 10.1111/jeu.12691.

Adl S.M., Simpson G.B., Farmer M.A., Andersen R.A., Anderson O.R., Barta J.R., Bowser S.S., Brugerolle G., Fensome R.A., Fredericq S., James T.Y., Karpov S., Kugrens P., Krug J., Lane C.E., Lewis L.A., Lodge J., Lynn D.H., Mann D.G., Mccourt R.M., Mendoza L., Moestrup Ø., Mozley-Standridge S.E., Nerad, T.A., Shearer C.A., Smirnov A.V., Spiegel F.W. & Taylor M.F.J.R. 2005. The new higher level classification of eukaryotes with emphasis on the taxonomy of protists. Journal of Eukaryotic Microbiology 52, 399–451, doi: 10.1111/j.1550-7408.2005.00053.x.

Anderson O.R., Nigrini C., Boltovskoy D., Takahashi K. & Swanberg N.R., 2002. Class Polycystina. In J.J. Lee et al. (eds.): The second illustrated guide to the protozoa. Pp. 994–1022. Lawrence, KS: Society of Protozoologists.

Bernstein R.E., Betzer P.R. & Takahashi K. 1990. Radiolarians from the western North Pacific Ocean: a latitudinal study of their distributions and fluxes. Deep-Sea Research Part A 37, 1677–1696, doi: 10.1016/0198-0149(90)90071-3.

Biard T., Krause J.W., Stukel M.R. & Ohman M.D. 2018. The significance of giant Phaeodarians (Rhizaria) to biogenic silica export in the California Current ecosystem. Global Biogeochemical Cycles 32, 987–1004, doi: 10.1029/2018GB005877.

Biard T., Stemmann L., Picheral M., Mayot N., Vandromme P., Hauss H., Gorsky G., Guidi L., Kiko R. & Not F. 2016. In situ imaging reveals the biomass of giant protists in the global ocean. Nature 532, 504–507, doi: 10.1038/nature17652.

Bjørklund K.R. 1974. The seasonal occurrence and depth zonation of radiolarians in Korsfjorden, western Norway. Sarsia 56, 13–42, doi: 10.1080/00364827.1974.10411259.

Bjørklund K.R. 1976. Radiolaria from the Norwegian Sea, Leg 38 of the Deep Sea Drilling Project. Initial Reports of the Deep Sea Drilling Project 38, 1101–1168, doi: 10.2973/dsdp.proc.38.131.1976

Bjørklund K.R. 1985. Upper Weichselian–Holocene radiolarian stratigraphy in the Skagerrak (NE North Sea). Norsk Geologisk Tidsskrift 65, 103–106.

Bjørklund K.R., Hatakeda K., Kruglikova S.B. & Matul A.G. 2015. Amphimelissa setosa (Cleve) (Polycystina, Nassellaria)—a stratigraphic and paleoecological marker of migrating polar environments in the Northern Hemisphere during the quaternary. Stratigraphy 12, 23–37.

Bjørklund K.R., Itaki T. & Dolven J.K. 2014. Per Theodor Cleve: a short résumé and his radiolarian results from the Swedish Expedition to Spitsbergen in 1898. Journal of Micropalaeontology 33, 59–93, doi: 10.1144/jmpaleo2012-024.

Bjørklund K.R. & Kruglikova S.B. 2003. Polycystine radiolarians in surface sediments in the Arctic Ocean basins and marginal seas. Marine Micropaleontology 49, 231–273, doi: 10.1016/S0377-8398(03)00036-7.

Bjørklund K.R., Kruglikova S.B. & Hammer Ø. 2019. The radiolarian fauna during the Younger Dryas–Holocene transition in Andfjorden, northern Norway. Polar Research 38, article no. 3444, doi: 10.33265/polar.v38.3444.

Bjørklund K.R. & Swanberg N.R. 1987. The distribution of two morphotypes of the radiolarian Amphimelissa setosa Cleve (Nassellarida): a result of environmental variability? Sarsia 72, 245–254, doi: 10.1080/00364827.1987.10419721.

Boltovskoy D., Kogan M., Alder V.A. & Mianzan H. 2003. First record of a brackish radiolarian (Polycystina): Lophophaena rioplatensis n. sp. in the Río de la Plata estuary. Journal of Plankton Research 25, 1551–1559, doi: 10.1093/plankt/fbg107.

Bråte J., Krabberød A.K., Dolven J.K., Ose R.F., Kristensen T., Bjørklund K.R. & Shalchian-Tabrizi K. 2012. Radiolaria associated with large diversity of marine alveolates. Protist 163, 767–777, doi: 10.1016/j.protis.2012.04.004.

Capella-Gutiérrez S., Silla-Martínez J.M. & Gabaldón T. 2009. trimAl: a tool for automated alignment trimming in large-scale phylogenetic analyses. Bioinformatics 25, 1972–1973, doi: 10.1093/bioinformatics/btp348.

Carmack E. & Wassmann P. 2006. Food webs and physical–biological coupling on pan-Arctic shelves: unifying concept and comprehensive perspectives. Progress in Oceanography 71, 446–477, doi: 10.1016/j.pocean.2006.10.004.

Cavalier-Smith T. 1998. A revised six-kingdom system of life. Biological Reviews 73, 203–266, doi: 10.1017/S0006323198005167.

Cavalier-Smith T. 2002. The phagotrophic origin of eukaryotes and phylogenetic classification of protozoa. International Journal of Systematic and Evolutionary Microbiology 52, 297–354, doi: 10.1099/00207713-52-2-297.

Claparède E. & Lachmann J. 1858. Études sur les infusoires et les Rhizopodes. (Studies of infusoria and rhizopods.) Mémoires de l’Institut National Genevois 6, 261–482.

Cortese G. & Bjørklund K.R. 1998a. The taxonomy of boreal Atlantic Ocean Actinommida (Radiolaria). Micropaleontology 44, 149–160, doi: 10.2307/1486067.

Cortese G. & Bjørklund K.R. 1998b. Morphometry and taxonomy of Hexacontium species from western Norwegian fjords. Micropaleontology 44, 161–172, doi: 10.2307/1486068.

Del Campo J., Kolisko M., Boscaro V., Santoferrara L.F., Nenarokov S., Massana R., Guillou L., Simpson A., Berney C., de Vargas C., Brown M.W., Keeling P.J. & Wegener Parfrey L. 2018. EukRef: phylogenetic curation of ribosomal RNA to enhance understanding of eukaryotic diversity and distribution. PLoS Biology 16, e2005849, doi: 10.1371/journal.pbio.2005849.

Dolven J.K., Bjørklund K.R. & Itaki T. 2014. Jørgensen’s polycystine radiolarian slide collection and new species. Journal of Micropalaeontology 33, 21–58, doi: 10.1144/jmpaleo2012-027.

Dolven J.K., Lindqvist C., Albert V.A., Bjørklund K.R., Yuasa T., Takahashi O. & Mayama S. 2007. Molecular diversity of alveolates associated with neritic North Atlantic radiolarians. Protist 158, 65–76, doi: 10.1016/j.protis.2006.07.004.

Ehrenberg C.G. 1838. Über die Bildung der Kreidefelsen und des Kreidemergels durch unsichtbare Organismen. (On the formation of chalk cliffs and chalk marl by invisible organisms.) Abhandlungen der Königlichen Akademie der Wissenschaften zu Berlin 1838, 59–147.

Ehrenberg C.G. 1876. Fortsetzung der mikrogeologischen Studien als Gesammt-Uebersicht der mikroskopischen Paläontologie gleichartig analysirter Gebirgsarten der Erde, mit specieller Rücksicht auf den Polycystinen-Mergel von Barbados. (Continuation of the microgeological studies as a general overview of the microscopic palaeontology of the Earth’s rock types analysed in the same way, with special regard to the polycystine marl of Barbados.) Abhandlungen der Königliche Akademie der Wissenschaften zu Berlin 1875, 1–225.

Eilertsen H.C., Falk-Petersen S., Hopkins C.C.E. & Tande K. 1981. Ecological investigations on the plankton community of Balsfjorden, northern Norway: program for the project, study area, topography, and physical environment. Sarsia 66, 25–34, doi: 10.1080/00364827.1981.10414517.

Emery K.O. & Honjo S. 1979. Surface suspended matter off western Africa: relations of organic matter, skeletal debris and detrital minerals. Sedimentology 26, 775–794, doi: 10.1111/j.1365-3091.1979.tb00972.x.

Falkenhaug T., Tande K. & Timonin A. 1997. Spatio-temporal patterns in the copepod community in Malangen, northern Norway. Journal of Plankton Research 19, 449–468, doi: 10.1093/plankt/19.4.449.

Fol H. 1883. Sur le Sticholonche zanclea et un nouvel ordre de Rhizopodes. (On Sticholonchea zanclea and a new order of Rhizopoda.) Mémoires de l’Institut National Genevois 15, 1–35.

Goll R.M. 1968. Classification and phylogeny of Cenozoic Trissocyclidae (Radiolaria) in the Pacific and Caribbean basins. Part I. Journal of Paleontology 42, 1409–1432.

Guillou L., Bachar D., Audic S., Bass D., Berney C., Bittner L., Boutte C., Burgaud G., de Vargas C. & Decelle J. 2013. The Protist Ribosomal Reference Database (PR2): a catalog of unicellular eukaryote small sub-unit rRNA sequences with curated taxonomy. Nucleic Acids Research 41, D597–D604, doi: 10.1093/nar/gks1160.

Guindon S., Dufayard J.F., Lefort V., Anisimova M., Hordijk W. & Gascuel O. 2010. New algorithms and methods to estimate maximum-likelihood phylogenies: assessing the performance of PhyML 3.0. Systematic Biology 59, 307–321, doi: 10.1093/sysbio/syq010.

Haeckel E. 1862. Die Radiolarien (Rhizopoda Radiaria). Eine Monographie. (The radiolarians [Rhizopoda radiaria].) Berlin: Reimer.

Haeckel E. 1879. Über die Phaeodarien, eine neue Gruppe kieselschaliger mariner Rhizopoden. (On the Phaeodaria, a new group of siliceous marine rhizopods.) Jenaische Zeitschrift für Naturwissenschaft 14, 151–157.

Haeckel E. 1881. Prodromus Systematis Radiolarium, Entwurf eines Radiolarien-Systems auf Grund von Studien der Challenger-Radiolarien. (Preliminary publication on the Radiolaria, based on studies of the Challenger radiolarian species.) Jenaische Zeitschrift für Naturwissenschaft 15, 418–472.

Haeckel E. 1887. Report on the Radiolaria collected by the H.M.S. Challenger during the years 1873–1876. Report on the Scientific Results of the Voyage of H.M.S. Challenger during the years 1873–76. Zoology. Vol. 18. London: Her Majesty’s Stationary Office.

Hermansen O.H. 1974. Sognefjordens hydrografi og vannutveksling. (Sognefjord’s hydrography and water exchange.) MSc thesis, University of Bergen.

Hernández-Almeida I., Björklund K.R., Diz P., Kruglikova S., Ikenoue T., Matul A., Saavedra-Pellitero M. & Swanberg N. 2020. Life on the ice-edge: paleoenvironmental significance of the radiolarian species Amphimelissa setosa in the Northern Hemisphere. Quaternary Science Reviews 248, article no. 106565, doi: 10.1016/j.quascirev.2020.106565.

Hertwig R. 1877. Studien uber Rhizopoden. (Studies of Rhizopoda.) Jenaische Zeitschrift für Naturwissenschaft 11, 324–348.

Hertwig R. 1879. Der organismus der Radiolarien. (The organisms of the radiolarians.) Jenaische Denkschriften 2, 129–277.

Hoang D.T., Chernomor O., Von Haeseler A., Minh B.Q. & Vinh L.S. 2018. UFBoot2: improving the ultrafast bootstrap approximation. Molecular Biology and Evolution 35, 518–522, doi: 10.1093/molbev/msx281.

Ikenoue T., Bjørklund K.R., Dumitrica P., Krabberød A.K., Kimoto K., Matsuno K. & Harada N. 2016. Two new living Entactinaria (Radiolaria) species from the Arctic province: Joergensenium arcticum n. sp. and Joergensenium clevei n. sp. Marine Micropaleontology 124, 75–94, doi: 10.1016/j.marmicro.2016.02.003.

Ikenoue T., Bjørklund K.R., Fujiwara A., Uchimiya M., Kimoto K., Harada N. & Nishino S. 2019. Horizontal and vertical distribution of polycystine radiolarians in the western Arctic Ocean during the late summers of 2013 and 2015. Polar Biology 42, 285–305, doi: 10.1007/s00300-018-2421-3.

Ikenoue T., Bjørklund K.R., Kruglikova S.B., Onodera J., Kimoto K. & Harada N. 2015. Flux variations and vertical distributions of siliceous Rhizaria (Radiolaria and Phaeodaria) in the western Arctic Ocean: indices of environmental changes. Biogeosciences 12, 2019–2046, doi: 10.5194/bg-12-2019-2015.

Ikenoue T., Kimoto K., Nakamura Y., Bjørklund K.R., Kuramoto N., Ueki M., Ota Y., Onodera J., Harada N., Honda M.C., Sato M., Watanabe E., Itoh M., Nishino S. & Kikuchi T. 2021. New evaluation of species-specific biogenic silica flux of radiolarians (Rhizaria) in the western Arctic Ocean using microfocus x-ray computed tomography. Limnology Oceanography 66, 3901–3915, doi: 10.1002/lno.11928.

Ikenoue T., Kimoto K., Okazaki Y., Sato M., Honda M.C., Takahashi K., Harada N. & Fujiki T. 2019. Phaeodaria: an important carrier of particulate organic carbon in the mesopelagic twilight zone of the North Pacific Ocean. Global Biogeochemical Cycles 33, 1146–1160, doi: 10.1029/2019GB006258.

Ikenoue T., Okazaki Y., Takahashi K. & Sakamoto T. 2016. Bering Sea radiolarian biostratigraphy and paleoceanography at IODP Site U1341 during the last four million years. Deep-Sea Research Part II 125, 38–55, doi: 10.1016/j.dsr2.2015.03.004.

Institute of Marine Research 2023. Faste hydrografiske stasjoner. (Fixed hydrographical stations.) Accessed on the internet at http://www.imr.no/forskning/forskningsdata/stasjoner/index.html on 11 Apil 2023.

Jansen E. & Bjørklund K.R. 1985. Surface ocean circulation in the Norwegian Sea 15,000 BP to present. Boreas 14, 243–257, doi: 10.1111/j.1502-3885.1985.tb00729.x.

Jørgensen E. 1900. Protophyten und Protozöen im Plankton aus der norwegischen Westküste. (Protophytes and protozoa in plankton from the west coast of Norway.) Bergens Museums Aarbog 1899 6, 51–112.

Jørgensen E. 1905. The Protist plankton and the diatoms in bottom samples. Plates VIII–XVIII. Bergens Museums Skrifter 1, 49–151.

Katoh K. & Standley D.M. 2013. MAFFT multiple sequence alignment software version 7: improvements in performance and usability. Molecular Biology and Evolution 30, 772–780, doi: 10.1093/molbev/mst010.

Krabberød A.K., Bråte J., Dolven J.K., Ose R.F., Klaveness D., Kristensen T., Bjørklund K.R. & Shalchian-Tabrizi K. 2011. Radiolaria divided into Polycystina and Spasmaria in combined 18S and 28Sr DNA phylogeny. PLoS One 6, e23526, doi: 10.1371/journal.pone.0023526.

Laget M., Llopis Monferrer N., Maguer J.F., Leynaert A. & Biard T. 2023. Elemental content allometries and silicon uptake rates of planktonic Rhizaria: insights into their ecology and role in biogeochemical cycles. Limnology and Oceanography 68, 439–454, doi: 10.1002/lno.12284.

Lampitt R.S., Salter I. & Johns D. 2009. Radiolaria: major exporters of organic carbon to the deep ocean. Global Biogeochemical Cycles 23, GB1010, doi: 10.1029/2008GB003221.

Lazarus D., Suzuki N., Ishitani Y. & Takahashi K. 2021. Paleobiology of the polycystine Radiolaria. Chichester, UK: John Wiley and Sons.

Llopis Monferrer N., Boltovskoy D., Tréguer P., Sandin M.M., Not F. & Leynaert A. 2020. Estimating biogenic silica production of Rhizaria in the global ocean. Global Biogeochemical Cycles 34, e2019GB006286, doi: 10.1029/2019GB006286.

Llopis Monferrer N., Leynaert A., Tréguer P., Gutiérrez‐Rodríguez A., Moriceau B., Gallinari M., Latasa M., L’Helguen S., Maguer J.-F., Safi K., Pinkerton M.H. & Not F. 2021. Role of small Rhizaria and diatoms in the pelagic silica production of the Southern Ocean. Limnology and Oceanography 66, 2187–2202, doi: 10.1002/lno.11743.

Matul A.G. & Abelmann A. 2005. Pleistocene and Holocene distribution of the Radiolarian Amphimelissa setosa Cleve in the North Pacific and North Atlantic: evidence for water mass movement. Deep-Sea Research Part II 52, 2351–2364, doi: 10.1016/j.dsr2.2005.07.008.

Michaels A.F., Caron D.A., Swanberg N.R., Howse F.A. & Michaels C.M. 1995. Planktonic sarcodines (Acantharia, Radiolaria, Foraminifera) in surface waters near Bermuda: abundance, biomass and vertical flux. Journal of Plankton Research 17, 131–163, doi: 10.1093/plankt/17.1.131.

Minh B.Q., Schmidt H.A., Chernomor O., Schrempf D., Woodhams M.D., von Haeseler A. & Lanfear R. 2020. IQ-TREE 2: new models and efficient methods for phylogenetic inference in the genomic era. Molecular Biology and Evolution 37, 1530–1534, doi: 10.1093/molbev/msaa015.

Motoda S. 1959. Devices of simple plankton apparatus. Memoirs of the Faculty of Fisheries Hokkaido University 7, 73–94.

Müller J. 1858. Über die Thalassicollen, Polycystinen und Acanthometren des Mittelmeeres. (About the Thalassicolla, Polycystines and Acanthometra of the Mediterranean Sea.) Abhandlungen der Königliche Akademie der Wissenschaften zu Berlin 1858, 1–62.

Murray T.H. 1885. The Radiolaria. In C.W. Thomson & T.H. Murray (eds.): Report on the scientific results of the voyage of the H.M.S. Challenger during the years 1873–76. Narrative. Vol. 1. First Part. Pp. 219–227. London: Her Majesty’s Stationary Office.

Nakamura Y., Imai I., Yamaguchi A., Tuji A. & Suzuki N. 2013. Aulographis japonica sp. nov. (Phaeodaria, Aulacanthida, Aulacanthidae), an abundant zooplankton in the deep sea of the Sea of Japan. Plankton and Benthos Research 8, 107–115, doi: 10.3800/pbr.8.107.

Nakamura Y. & Suzuki N. 2015. Phaeodaria: diverse marine cercozoans of world-wide distribution. In S. Ohtsuka et al. (eds.): Marine protists. Pp. 223–249. Tokyo, Japan: Springer.

Nishino S., Kikuchi T., Yamamoto-Kawai M., Kawaguchi Y., Hirawake T. & Itoh M. 2011. Enhancement/reduction of biological pump depends on ocean circulation in the sea-ice reduction regions of the Arctic Ocean. Journal of Oceanography 67, 305–314, doi: 10.1007/s10872-011-0030-7.

Polet S., Berney C., Fahrni J. & Pawlowski J. 2004. Small subunit ribosomal RNA gene sequences of Phaeodarea challenge the monophyly of Haeckel’s Radiolaria. Protist 155, 53–63, doi: 10.1078/1434461000164.

Reβ T. 2015. Some hydrographical changes in the Sognefjord and its tributaries, the Sogndalsfjord and the Barsnesfjord (Western Norway), the last century. Bachelor’s thesis, Sogn og Fjordane University College, Norway.

Riedel W.R. 1967. Subclass radiolaria. In W.B. Harland et al. (eds.): The fossil record: a symposium with documentation. Pp. 291–298. London: Geological Society of London.

Schröder-Ritzrau A., Andruleit H., Jensen S., Samtleben C., Schäfer P., Matthiessen J., Hass, H.C., Kohly A. & Thiede J. 2001. Distribution, export and alteration of fossilizable plankton in the Nordic Seas. In P. Schäfer et al. (eds.): The northern North Atlantic: a changing environment. Pp. 81–104. Berlin: Springer.

Steinberg D.K., Cope J.S., Wilson S.E. & Kobari T. 2008. A comparison of mesopelagic mesozooplankton community structure in the subtropical and Subarctic North Pacific Ocean. Deep-Sea Research Part II 55, 1615–1635, doi: 10.1016/j.dsr2.2008.04.025.

Stukel M.R., Biard T., Krause J. & Ohman M.D. 2018. Large Phaeodaria in the twilight zone: their role in the carbon cycle. Limnology and Oceanography 63, 2579–2594, doi: 10.1002/lno.10961.

Suzuki N. & Not F. 2015. Biology and ecology of Radiolaria. In S. Ohtsuka et al. eds.): Marine protists. Tokyo: Springer.

Swanberg N.R. & Bjørklund K.R. 1986. The radiolarian fauna of western Norwegian fjords: patterns of abundance in the plankton. Marine Micropaleontology 11, 231–241, doi: 10.1016/0377-8398(86)90017-4.

Swanberg N.R. & Bjørklund K.R. 1987. Radiolaria in the plankton of some fjords in western and northern Norway: the distribution of species. Sarsia 72, 231–244, doi: 10.1080/00364827.1987.10419720.

Swanberg N.R. & Bjørklund K.R. 1992. The radiolarian fauna of western Norwegian fjords: a multivariate comparison of the sediment and plankton assemblages. Micropaleontology 38(4), 57–74, doi: 10.2307/1485843.

Swanberg N.R. & Eide L.K. 1992. The radiolarian fauna at the ice edge in the Greenland Sea during summer, 1988. Journal of Marine Research 50, 297–320, doi: 10.1357/002224092784797674.

Takahashi K. 1991. Mineral flux and biogeochemical cycles of marine planktonic protozoa—session summary. In P.C. Reid et al. (eds.): Protozoa and their role in marine processes. Pp. 347–359. Berlin: Springer.

Takahashi K. & Anderson O.R. 2002. Class Phaeodaria. In J.J. Lee et al. (eds.): The second illustrated guide to the Protozoa. Pp. 981–994. Lawrence, KS: Society of Protozoologists.

Takahashi K., Hurd D.C. & Honjo S. 1983. Phaeodarian skeletons: their role in silica transport to the deep sea. Science 222, 616–618, doi: 10.1126/science.222.4624.616.

Takahashi K. & Ling H.Y. 1980. Distribution of Sticholonche (Radiolaria) in the upper 800 m of the waters in the Equatorial Pacific. Marine Micropaleontology 5, 311–319, doi: 10.1016/0377-8398(80)90015-8.

Tan Z.Y., Gao H.Z. & Su X.H. 1978. The quantitative distribution of Sticholonche zanclea in the western part of the East China Sea. Oceanologia et Limnologia Sinica 9, 59–66. (In Chinese, with English abstract.)

Wassmann P., Svendsen H., Keck A. & Reigstad M. 1996. Selected aspects of the physical oceanography and particle fluxes in fjords of northern Norway. Journal of Marine Systems 8, 53–71, doi: 10.1016/0924-7963(95)00037-2.

Welling L.A. 1996. Environmental control of radiolarian abundance in the central Equatorial Pacific and implications for paleoceanographic reconstructions. PhD thesis, Oregon State University, Corvallis.

Yuasa T., Dolven J.K., Bjørklund K.R., Mayama S. & Takahashi O. 2009. Molecular phylogenetic position of Hexacontium pachydermum Jørgensen (Radiolaria). Marine Micropaleontology 73, 129–134, doi: 10.1016/j.marmicro.2009.08.001.

Yuasa T., Takahashi O., Dolven J.K., Mayama S., Matsuoka A., Honda D. & Bjørklund K.R. 2006. Phylogenetic position of the small solitary phaeodarians (Radiolaria) based on 18S rDNA sequences by single cell PCR analysis. Marine Micropaleontology 59, 104–114, doi: 10.1016/j.marmicro.2006.01.003.