We analysed a widely used barcode, the V9 region of the 18S rRNA gene, to study the effect of environmental conditions on the distribution of two related heterotrophic protistan lineages in marine plankton, kinetoplastids and diplonemids. We relied on a major published dataset (Tara Oceans) where samples from the mesopelagic zone were available from just 32 of 123 locations, and both groups are most abundant in this zone. To close sampling gaps and obtain more information from the deeper ocean, we collected 57 new samples targeting especially the mesopelagic zone. We sampled in three geographic regions: the Arctic, two depth transects in the Adriatic Sea, and the anoxic Cariaco Basin. In agreement with previous studies, both protist groups are most abundant and diverse in the mesopelagic zone. In addition to that, we found that their abundance, richness, and community structure also depend on geography, oxygen concentration, salinity, temperature, and other environmental variables reflecting the abundance of algae and nutrients. Both groups studied here demonstrated similar patterns, although some differences were also observed. Kinetoplastids and diplonemids prefer tropical regions and nutrient-rich conditions and avoid high oxygen concentration, high salinity, and high density of algae.

Biocenter University of Würzburg Würzburg Germany

Department of Human Evolutionary Biology Harvard University Cambridge MA USA

Department of Molecular Biology Faculty of Science University of South Bohemia České Budějovice Czech Republic

Geology and Geophysics Department Woods Hole Oceanographic Institution Woods Hole Massachusetts USA

Institute of Oceanography and Fisheries Split Croatia

Institute of Oceanology Polish Academy of Sciences Sopot Poland

Institute of Parasitology Biology Centre Czech Academy of Sciences České Budějovice Czech Republic

Life Science Research Centre Faculty of Science University of Ostrava Ostrava Czech Republic

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Atkins, M.S., Teske, A.P., and Anderson, O.R. (2000) A survey of flagellate diversity at four deep-sea hydrothermal vents in the eastern Pacific Ocean using structural and molecular approaches. J Euk Microbiol 47: 400-411..

Atkinson, D., Ciotti, B.J., and Montagnes, D.J.S. (2003) Protists decrease in size linearly with temperature: ca. 2.5%°C. Proc R Soc Lond B Biol Sci 270: 2605-2611. https://doi.org/10.1098/rspb.2003.2538.

Boenigk, J., Ereshefsky, M., Hoef-Emden, K., Mallet, J., and Bass, D. (2012) Concepts in protistology: species definitions and boundaries. Eur J Protistol 48: 96-102. https://doi.org/10.1016/j.ejop.2011.11.004.

Bråte, J., Krabberød, A.K., Dolven, J.K., Ose, R.F., Kristensen, T., Bjørklund, K.R., and Shalchian-Tabrizi, K. (2012) Radiolaria associated with large diversity of marine Alveolates. Protist 163: 767-777. https://doi.org/10.1016/J.PROTIS.2012.04.004.

Brayard, A., Escarguel, G., and Bucher, H. (2005) Latitudinal gradient of taxonomic richness: combined outcome of temperature and geographic mid-domains effects? J Zoolog Syst Evol Res 43: 178-188. https://doi.org/10.1111/j.1439-0469.2005.00311.x.

Brown, P.B., and Wolfe, G.V. (2006) Protist genetic diversity in the acidic hydrothermal environments of Lassen volcanic National Park, USA. J Euk Microbiol 53: 420-431. https://doi.org/10.1111/j.1550-7408.2006.00125.x.

Calbet, A., and Landry, M.R. (2004) Phytoplankton growth, microzooplankton grazing, and carbon cycling in marine systems. Limnol Oceanogr 49: 51-57. https://doi.org/10.4319/lo.2004.49.1.0051.

Callahan, H.A., Litaker, R.W., and Noga, E.J. (2002) Molecular taxonomy of the suborder Bodonina (order Kinetoplastida), including the important Fish parasite, Ichthyobodo necator. J Euk Microbiol 49: 119-128. https://doi.org/10.1111/j.1550-7408.2002.tb00354.x.

Cavalier-Smith, T. (2016) Higher classification and phylogeny of Euglenozoa. Eur J Protistol 56: 250-276. https://doi.org/10.1016/J.EJOP.2016.09.003.

Chambouvet, A., Morin, P., Marie, D., and Guillou, L. (2008) Control of toxic marine dinoflagellate blooms by serial parasitic killers. Science 322: 1254-1257. https://doi.org/10.1126/science.1164387.

Chen, J., Hanke, A., Tegetmeyer, H.E., Kattelmann, I., Sharma, R., Hamann, E., et al. (2017) Impacts of chemical gradients on microbial community structure. ISME J 11: 920-931. https://doi.org/10.1038/ismej.2016.175.

Costello, M.J., and Chaudhary, C. (2017) Marine biodiversity, biogeography, Deep-Sea gradients, and conservation. Curr Biol 27: R511-R527. https://doi.org/10.1016/J.CUB.2017.04.060.

Countway, P.D., Gast, R.J., Dennett, M.R., Savai, P., Rose, J.M., and Caron, D.A. (2007) Distinct protistan assemblages characterize the euphotic zone and deep sea (2500 m) of the western North Atlantic (Sargasso Sea and gulf stream). Environ Microbiol 9: 1219-1232. https://doi.org/10.1111/j.1462-2920.2007.01243.x.

de Vargas, C., Audic, S., Henry, N., Decelle, J., Mahé, F., Logares, R., et al. (2015) Eukaryotic plankton diversity in the sunlit ocean. Science 348: 1261605. https://doi.org/10.1126/science.1261605.

del Campo, J., Sieracki, M.E., Molestina, R., Keeling, P., Massana, R., and Ruiz-Trillo, I. (2014) The others: our biased perspective of eukaryotic genomes. Trends Ecol Evol 29: 252-259. https://doi.org/10.1016/J.TREE.2014.03.006.

Ebenezer, T., Zoltner, M., Burrel, A., Nenarokova, A., Vanclová, A., Prasad, B., et al. (2019) Transcriptome, proteome and draft genome of Euglena gracilis. BMC Biol 17: 11.

Edgcomb, V.P. (2016) Marine protist associations and environmental impacts across trophic levels in the twilight zone and below. Curr Opin Microbiol 31: 169-175. https://doi.org/10.1016/j.mib.2016.04.001.

Edgcomb, V.P., Orsi, W., Bunge, J., Jeon, S., Christen, R., Leslin, C., et al. (2011) Protistan microbial observatory in the Cariaco Basin, Caribbean. I. Pyrosequencing vs. Sanger insights into species richness. ISME J 5: 1344-1356. https://doi.org/10.1038/ismej.2011.6.

El-Sayed, N.M., Myler, P.J., Blandin, G., Berriman, M., Crabtree, J., Aggarwal, G., et al. (2005) Comparative genomics of trypanosomatids. Science 309: 404-409. https://doi.org/10.1126/science.1112181.

Elbrächter, M., Schnepf, E., and Balzer, I. (1996) Hemistasia phaeocysticola (Scherffel) comb. nov., Redescription of a free-living, marine, Phagotrophic Kinetoplastid flagellate. Arch Protistenkunde 147: 125-136. https://doi.org/10.1016/S0003-9365(96)80028-5.

Eloe, E.A., Shulse, C.N., Fadrosh, D.W., Williamson, S.J., Allen, E.E., and Bartlett, D.H. (2011) Compositional differences in particle-associated and free-living microbial assemblages from an extreme deep-ocean environment. Environ Microbiol Rep 3: 449-458. https://doi.org/10.1111/j.1758-2229.2010.00223.x.

Fenchel, T., and Bernard, C. (1996) Behavioural responses in oxygen gradients of ciliates from microbial mats. Eur J Protistol 32: 55-63. https://doi.org/10.1016/S0932-4739(96)80039-3.

Fenchel, T., Bernard, C., Esteban, G., Finlay, B.J., Hansen, P.J., and Iversen, N. (1995) Microbial diversity and activity in a Danish Fjord with anoxic deep water. Ophelia 43: 45-100. https://doi.org/10.1080/00785326.1995.10430576.

Fenchel, T., and Finlay, B.J. (1990) Oxygen toxicity, respiration and behavioural responses to oxygen in free-living anaerobic ciliates. J Gen Microbiol 136: 1953-1959. https://doi.org/10.1099/00221287-136-10-1953.

Fenchel, T., and Finlay, B.J. (2008) Oxygen and the spatial structure of microbial communities. Biol Rev 83: 553-569. https://doi.org/10.1111/j.1469-185X.2008.00054.x.

Fenchel, T., Finlay, B.J., and Giannì, A. (1989) Microaerophily in ciliates: responses of an Euplotes species (hypotrichida) to oxygen tension. Arch Protistenkunde 137: 317-330. https://doi.org/10.1016/S0003-9365(89)80015-6.

Finlay, B.J., and Fenchel, T. (2004) Cosmopolitan metapopulations of free-living microbial eukaryotes. Protist 155: 237-244.

Flegontova, O., Flegontov, P., Malviya, S., Audic, S., Wincker, P., de Vargas, C., et al. (2016) Extreme diversity of diplonemid eukaryotes in the ocean. Curr Biol 26: 3060-3065. https://doi.org/10.1016/j.cub.2016.09.031.

Flegontova, O., Flegontov, P., Malviya, S., Poulain, J., de Vargas, C., Bowler, C., et al. (2018) Neobodonids are dominant kinetoplastids in the global ocean. Environ Microbiol 20: 878-889. https://doi.org/10.1111/1462-2920.14034.

Foissner, W. (2006) Biogeography and dispersal of micro-organisms: a review emphasizing protists. Acta Protozool 45: 111-136.

Fuhrman, J.A., Steele, J.A., Hewson, I., Schwalbach, M.S., Brown, M.V., Green, J.L., and Brown, J.H. (2008) A latitudinal diversity gradient in planktonic marine bacteria. Proc Natl Acad Sci U S A 105: 7774-7778. https://doi.org/10.1073/pnas.0803070105.

Gawryluk, R.M.R., del Campo, J., Okamoto, N., Strassert, J.F.H., Lukeš, J., Richards, T.A., et al. (2016) Morphological identification and single-cell genomics of marine diplonemids. Curr Biol 26: 3053-3059. https://doi.org/10.1016/j.cub.2016.09.013.

Gimmler, A., Korn, R., De Vargas, C., Audic, S., and Stoeck, T. (2016) The Tara oceans voyage reveals global diversity and distribution patterns of marine planktonic ciliates. Sci Rep 6: 33555. https://doi.org/10.1038/srep33555.

Giner, C.R., Forn, I., Romac, S., Logares, R., de Vargas, C., and Massana, R. (2016) Environmental sequencing provides reasonable estimates of the relative abundance of specific picoeukaryotes. Appl Environ Microbiol 82: 4757-4766. https://doi.org/10.1128/AEM.00560-16.

Gooday, A.J., Bernhard, J.M., Levin, L.A., and Suhr, S.B. (2000) Foraminifera in the Arabian Sea oxygen minimum zone and other oxygen-deficient settings: taxonomic composition, diversity, and relation to metazoan faunas. Deep Sea Res Part 2 Top Stud Oceanogr 47: 25-54. https://doi.org/10.1016/S0967-0645(99)00099-5.

Guillou, L., Viprey, M., Chambouvet, A., Welsh, R.M., Kirkham, A.R., Massana, R., et al. (2008) Widespread occurrence and genetic diversity of marine parasitoids belonging to Syndiniales ( Alveolata ). Environ Microbiol 10: 3349-3365. https://doi.org/10.1111/j.1462-2920.2008.01731.x.

Guillou, L., Bachar, D., Audic, S., Bass, D., Berney, C., Bittner, L., and Christen, R. (2013) The Protist ribosomal reference database (PR2): a catalog of unicellular eukaryote small sub-unit rRNA sequences with curated taxonomy. Nucleic Acids Res 41: D597-D604. https://doi.org/10.1093/nar/gks1160.

Hamilton, P.B., Gibson, W.C., and Stevens, J.R. (2007) Patterns of co-evolution between trypanosomes and their hosts deduced from ribosomal RNA and protein-coding gene phylogenies. Mol Phyl Evol 44: 15-25. https://doi.org/10.1016/j.ympev.2007.03.023.

Hellweger, F.L., van Sebille, E., and Fredrick, N.D. (2014) Biogeographic patterns in ocean microbes emerge in a neutral agent-based model. Science 345: 1346-1349.

Hillebrand, H., and Azovsky, A.I. (2001) Body size determines the strength of the latitudinal diversity gradient. Ecography 24: 251-256. https://doi.org/10.1111/j.1600-0587.2001.tb00197.x.

Ibarbalz, F.M., Henry, N., Brandao, M.C., Martini, S., Busseni, G., Byrne, H., et al. (2019) Global trends in marine plankton diversity across kingdoms of life. Cell 179: 1084-1097. https://doi.org/10.1016/j.cell.2019.10.008.

Ikeda, T. (2017) An analysis of metabolic characteristics of planktonic heterotrophic protozoans. J Plankton Res 39: 479-490. https://doi.org/10.1093/plankt/fbx015.

Keeling, P.J., and del Campo, J. (2017) Marine protists are not just big bacteria. Curr Biol 27: R541-R549. https://doi.org/10.1016/j.cub.2017.03.075.

Kelly, R.P., Shelton, A.O., and Gallego, R. (2019) Understanding PCR processes to draw meaningful conclusions from environmental DNA studies. Sci Rep 9: 12133.

Kent, M.L., Elston, R.A., Nerad, T.a., and Sawyer, T.K. (1987) An Isonema-like flagellate (protozoa: Mastigophora) infection in larval geoduck clams, Panope abrupta. J Inv Pathol 50: 221-229. https://doi.org/10.1016/0022-2011(87)90086-3.

Khomich, M., Kauserud, H., Logares, R., Rasconi, S., and Andersen, T. (2017) Planktonic protistan communities in lakes along a large-scale environmental gradient. FEMS Microbiol Ecol 93: fiw231.

Lara, E., Moreira, D., Vereshchaka, A., and López-García, P. (2009) Pan-oceanic distribution of new highly diverse clades of deep-sea diplonemids. Environ Microbiol 11: 47-55. https://doi.org/10.1111/j.1462-2920.2008.01737.x.

Larsen, J., and Patterson, J. (1990) Some flagellates (Protista) from tropical marine sediments. J Nat Hist 24: 801-937.

Lima-Mendez, G., Faust, K., Henry, N., Decelle, J., Colin, S., Carcillo, F., et al. (2015) Determinants of community structure in the global plankton interactome. Science 348: 1262073. https://doi.org/10.1126/science.1262073.

Lin, X., Scranton, M., Varela, R., Chistoserdov, A., and Taylor, G. (2007) Compositional responses of bacterial communities to redox gradients and grazing in the anoxic Cariaco Basin. Aquat Microb Ecol 47: 57-72. https://doi.org/10.3354/ame047057.

Logares, R., Audic, S., Bass, D., Bittner, L., Boutte, C., Christen, R., et al. (2014) Patterns of rare and abundant marine microbial eukaryotes. Curr Biol 24: 813-821. https://doi.org/10.1016/j.cub.2014.02.050.

Logares, R., Deutschmann, I.M., Junger, P.C., Giner, C.R., Krabberød, A.K., Schmidt, T.S.B., et al. (2020) Disentangling the mechanisms shaping the surface ocean microbiota. Microbiome 8: 55. https://doi.org/10.21203/rs.2.17228/v1.

Longhurst, A.R. (2007) Ecological Geography of the Sea, London: Academic Press. https://doi.org/10.1016/B978-0-12-455521-1.X5000-1.

López-García, P., Philippe, H., Gail, F., and Moreira, D. (2003) Autochthonous eukaryotic diversity in hydrothermal sediment and experimental microcolonizers at the mid-Atlantic ridge. Proc Natl Acad Sci U S A 100: 697-702. https://doi.org/10.1073/pnas.0235779100.

Lukeš, J., Skalický, T., Týč, J., Votýpka, J., and Yurchenko, V. (2014) Evolution of parasitism in kinetoplastid flagellates. Mol Biochem Parasitol 195: 115-122. https://doi.org/10.1016/j.molbiopara.2014.05.007.

Mahé, F., Rognes, T., Quince, C., de Vargas, C., and Dunthorn, M. (2015) Swarm v2: highly-scalable and high-resolution amplicon clustering. PeerJ 3: e1420. https://doi.org/10.7717/peerj.1420.

Malviya, S., Scalco, E., Audic, S., Vincent, F., Veluchamy, A., Poulain, J., et al. (2016) Insights into global diatom distribution and diversity in the world's ocean. Proc Natl Acad Sci U S A 113: E1516-E1525.

Maslov, D.A., Votýpka, J., Yurchenko, V., and Lukeš, J. (2013) Diversity and phylogeny of insect trypanosomatids: all that is hidden shall be revealed. Trends Parasitol 29: 43-52. https://doi.org/10.1016/j.pt.2012.11.001.

Massana, R., del Campo, J., Sieracki, M.E., Audic, S., and Logares, R. (2014) Exploring the uncultured microeukaryote majority in the oceans: reevaluation of ribogroups within stramenopiles. ISME J 8: 854-866. https://doi.org/10.1038/ismej.2013.204.

Medlyn, B.E., Dreyer, E., Ellsworth, D., Forstreuter, M., Harley, P.C., Kirschbaum, M.U.F., et al. (2002) Temperature response of parameters of a biochemically based model of photosynthesis. II. A review of experimental data. Plant Cell Environ 25: 1167-1179. https://doi.org/10.1046/j.1365-3040.2002.00891.x.

Moreira, D., López-García, P., and Vickerman, K. (2004) An updated view of kinetoplastid phylogeny using environmental sequences and a closer outgroup: proposal for a new classification of the class Kinetoplastea. Int J Syst Evol Microbiol 54: 1861-1875. https://doi.org/10.1099/ijs.0.63081-0.

Morgan-Smith, D., Herndl, G., van Aken, H., and Bochdansky, A. (2011) Abundance of eukaryotic microbes in the deep subtropical North Atlantic. Aquat Microb Ecol 65: 103-115. https://doi.org/10.3354/ame01536.

Mukherjee, I., Hodoki, Y., and Nakano, S.-I. (2015) Kinetoplastid flagellates overlooked by universal primers dominate in the oxygenated hypolimnion of Lake Biwa, Japan. FEMS Microbiol Ecol 91: fiv083. https://doi.org/10.1093/femsec/fiv083.

Noll, M., Matthies, D., Frenzel, P., Derakshani, M., and Liesack, W. (2005) Succession of bacterial community structure and diversity in a paddy soil oxygen gradient. Environ Microbiol 7: 382-395. https://doi.org/10.1111/j.1462-2920.2005.00700.x.

O'Neill, E.C., Trick, M., Henrissat, B., and Field, R.A. (2015) Euglena in time: evolution, control of central metabolic processes and multi-domain proteins in carbohydrate and natural product biochemistry. Perspect Sci 6: 84-93. https://doi.org/10.1016/J.PISC.2015.07.002.

Okamoto, N., Gawryluk, R.M.R., del Campo, J., Strassert, J.F.H., Lukeš, J., Richards, T.A., et al. (2019) A revised taxonomy of Diplonemids including the Eupelagonemidae n. fam. and a type species, Eupelagonema oceanica n. gen. and n. sp. J Euk Microbiol 66: 519-524. https://doi.org/10.1111/jeu.12679.

Pachiadaki, M.G., Taylor, C., Oikonomou, A., Yakimov, M.M., Stoeck, T., and Edgcomb, V.P. (2016) In situ grazing experiments apply new technology to gain insights into deep-sea microbial food webs. Deep Sea Res Part 2 Top Stud Oceanogr 129: 223-231. https://doi.org/10.1016/J.DSR2.2014.10.019.

Pernice, M.C., Giner, C.R., Logares, R., Perera-Bel, J., Acinas, S.G., Duarte, C.M., et al. (2015) Large variability of bathypelagic microbial eukaryotic communities across the world's oceans. ISME J 10: 1-14. https://doi.org/10.1038/ismej.2015.170.

Porter, D. (1973) Isonema papillatum sp. n., a new colorless marine flagellate: a light- and electronmicroscopic study. J Protozool 20: 351-356. https://doi.org/10.1111/j.1550-7408.1973.tb00895.x.

Righetti, D., Vogt, M., Gruber, N., Psomas, A., and Zimmermann, N.E. (2019) Global pattern of phytoplankton diversity driven by temperature and environmental variability. Sci Adv 5: eaau6253.

Rocke, E., Pachiadaki, M.G., Cobban, A., Kujawinski, E.B., and Edgcomb, V.P. (2015) Protist community grazing on prokaryotic prey in deep ocean water masses. PLoS One 10: e0124505. https://doi.org/10.1371/journal.pone.0124505.

Rodríguez-Zavala, J.S., Ortiz-Cruz, M.A., Mendoza-Hernández, G., and Moreno-Sánchez, R. (2010) Increased synthesis of α-tocopherol, paramylon and tyrosine by Euglena gracilis under conditions of high biomass production. J Appl Microbiol 109: 2160-2172. https://doi.org/10.1111/j.1365-2672.2010.04848.x.

Salani, F.S., Arndt, H., Hausmann, K., Nitsche, F., and Scheckenbach, F. (2012) Analysis of the community structure of abyssal kinetoplastids revealed similar communities at larger spatial scales. ISME J 6: 713-723. https://doi.org/10.1038/ismej.2011.138.

Sauvadet, A.L., Gobet, A., and Guillou, L. (2010) Comparative analysis between protist communities from the deep-sea pelagic ecosystem and specific deep hydrothermal habitats. Environ Microbiol 12: 2946-2964. https://doi.org/10.1111/j.1462-2920.2010.02272.x.

Schabhüttl, S., Hingsamer, P., Weigelhofer, G., Hein, T., Weigert, A., and Striebel, M. (2013) Temperature and species richness effects in phytoplankton communities. Oecologia 171: 527-536. https://doi.org/10.1007/s00442-012-2419-4.

Scheckenbach, F., Hausmann, K., Wylezich, C., Weitere, M., and Arndt, H. (2010) Large-scale patterns in biodiversity of microbial eukaryotes from the abyssal sea floor. Proc Natl Acad Sci U S A 107: 115-120. https://doi.org/10.1073/pnas.0908816106.

Šimek, K., Hartman, P., Nedoma, J., Pernthaler, J., Springmann, D., Vrba, J., and Psenner, R. (1997) Community structure, picoplankton grazing and zooplankton control of heterotrophic nanoflagellates in a eutrophic reservoir during the summer phytoplankton maximum. Aquat Microb Ecol 12: 49-63. https://doi.org/10.3354/ame012049.

Simpson, A.G., and Roger, A.J. (2004) Protein phylogenies robustly resolve the deep-level relationships within Euglenozoa. Mol Phyl Evol 30: 201-212. https://doi.org/10.1016/S1055-7903(03)00177-5.

Simpson, A.G.B., Lukeš, J., and Roger, A.J. (2002) The evolutionary history of Kinetoplastids and their Kinetoplasts. Mol Biol Evol 19: 2071-2083. https://doi.org/10.1093/oxfordjournals.molbev.a004032.

Soininen, J., Jamoneau, A., Rosebery, J., and Passy, S.I. (2016) Global patterns and drivers of species and trait composition in diatoms. Glob Ecol Biogeogr 25: 940-950. https://doi.org/10.1111/geb.12452.

Šolić, M., and Krstulović, N. (1994) Role of predation in controlling bacterial and heterotrophic nanoflagellate standing stocks in the coastal Adriatic Sea: seasonal patterns. Mar Ecol Prog Ser 114: 219-235.

Šolić, M., Šantić, D., Šestanović, S., Bojanić, N., Ordulj, M., Jozić, S., and Vrdoljak, A. (2018) The effect of temperature increase on microbial carbon fluxes in the Adriatic Sea: an experimental approach. FEMS Microbiol Ecol 94: fiy169.

Šolić, M., Šantić, D., Šestanović, S., Bojanić, N., Jozić, S., Vrdoljak, A., et al. (2019) Temperature and phosphorus interacts in controlling the picoplankton carbon flux in the Adriatic Sea: an experimental versus field study. Environ Microbiol 21: 2469-2484. https://doi.org/10.1111/1462-2920.14634.

Stock, A., Breiner, H.-W., Pachiadaki, M., Edgcomb, V.P., Filker, S., La Cono, V., et al. (2012) Microbial eukaryote life in the new hypersaline deep-sea basin Thetis. Extremophiles 16: 21-34. https://doi.org/10.1007/s00792-011-0401-4.

Stoeck, T., Bass, D., Nebel, M., Christen, R., Jones, M.D.M., Breiner, H.-W., and Richards, T.A. (2010) Multiple marker parallel tag environmental DNA sequencing reveals a highly complex eukaryotic community in marine anoxic water. Mol Ecol 19: 21-31. https://doi.org/10.1111/j.1365-294X.2009.04480.x.

Tashyreva, D., Prokopchuk, G., Yabuki, A., Kaur, B., Faktorová, D., Votýpka, J., et al. (2018) Phylogeny and morphology of new diplonemids from Japan. Protist 169: 158-179. https://doi.org/10.1016/J.PROTIS.2018.02.001.

Thomas, M.K., Kremer, C.T., Klausmeier, C.A., and Litchman, E. (2012) A global pattern of thermal adaptation in marine phytoplankton. Science 338: 1085-1088. https://doi.org/10.1126/science.1224836.

Tillmann, U. (2004) Interactions between planktonic microalgae and protozoan Grazers1. J Euk Microbiol 51: 156-168. https://doi.org/10.1111/j.1550-7408.2004.tb00540.x.

Toseland, A., Daines, S.J., Clark, J.R., Kirkham, A., Strauss, J., Uhlig, C., et al. (2013) The impact of temperature on marine phytoplankton resource allocation and metabolism. Nat Clim Chang 3: 979-984. https://doi.org/10.1038/nclimate1989.

von der Heyden, S., and Cavalier-Smith, T. (2005) Culturing and environmental DNA sequencing uncover hidden kinetoplastid biodiversity and a major marine clade within ancestrally freshwater Neobodo designis. Int J Syst Evol Microbiol 55: 2605-2621. https://doi.org/10.1099/ijs.0.63606-0.

von der Heyden, S., Chao, E.E., Vickerman, K., and Cavalier-Smith, T. (2004) Ribosomal RNA phylogeny of bodonid and diplonemid flagellates and the evolution of euglenozoa. J Euk Microbiol 51: 402-416. https://doi.org/10.1111/j.1550-7408.2004.tb00387.x.

Weisse, T., Karstens, N., Meyer, V., Janke, L., Lettner, S., and Teichgräber, K. (2001) Niche separation in common prostome freshwater ciliates: the effect of food and temperature. Aquat Microb Ecol 26: 167-179. https://doi.org/10.3354/ame026167.

Worden, A.Z., Follows, M.J., Giovannoni, S.J., Wilken, S., Zimmerman, A.E., and Keeling, P.J. (2015) Rethinking the marine carbon cycle: factoring in the multifarious lifestyles of microbes. Science 347: 1257594. https://doi.org/10.1126/science.1257594.

Yabuki, A., and Tame, A. (2015) Phylogeny and reclassification of Hemistasia phaeocysticola (Scherffel) Elbrächter & Schnepf, 1996. J Euk Microbiol 62: 426-429. https://doi.org/10.1111/jeu.12191.

Yazaki, E., Ishikawa, S.A., Kume, K., Kumagai, A., Kamaishi, T., Tanifuji, G., et al. (2017) Global Kinetoplastea phylogeny inferred from a large-scale multigene alignment including parasitic species for better understanding transitions from a free-living to a parasitic lifestyle. Genes Genet Syst 92: 35-42. https://doi.org/10.1266/ggs.16-00056.

Zhao, F., Filker, S., Xu, K., Huang, P., and Zheng, S. (2017) Patterns and drivers of vertical distribution of the ciliate community from the surface to the abyssopelagic zone in the Western Pacific Ocean. Front Microbiol 8: 2559. https://doi.org/10.3389/fmicb.2017.02559.

On the possibility of yet a third kinetochore system in the protist phylum Euglenozoa

Intragenomic diversity of the V9 hypervariable domain in eukaryotes has little effect on metabarcoding

Functional differentiation of Sec13 paralogues in the euglenozoan protists

Recent expansion of metabolic versatility in Diplonema papillatum, the model species of a highly speciose group of marine eukaryotes

Massive Accumulation of Strontium and Barium in Diplonemid Protists

Water masses shape pico-nano eukaryotic communities of the Weddell Sea

Trophic flexibility of marine diplonemids - switching from osmotrophy to bacterivory

Highly flexible metabolism of the marine euglenozoan protist Diplonema papillatum

Euglenozoa: taxonomy, diversity and ecology, symbioses and viruses