Supplementary information to Bråte et al. 2010 Table S1. Showing the studies reporting 18S rDNA environmental sequences that were used in BLAST searches in this study. Study Habitat Size fraction (µm) Sequence used in BLAST search Diez et al. (2001) Marine 0.2 to 5 AF363210 Edgcomb et al. (2002) Marine Whole community No Lopez-Garcia et al. (2003) Marine Whole community AF530536 AF530535 AF530534 Massana et al. (2004) Marine 0.2 to 3 No Behnke et al. (2006) Marine 0.7 No Lovejoy et al. (2006) Marine 0.2 to 3 No Zuendorf et al. (2006) Marine 0.7 DQ103802 Dalby et al. (2008) Marine 1 to 10 No Countway et al. (2005) Freshwater 0.7 AY938174 Richards et al. (2005) Freshwater 0.2 AY919735 Slapeta et al. (2005) Freshwater 0.2 to 5 No Lefranc et al. (2005) Freshwater 0.2 to 5 AY642737 AY642738 AY642744 Lefèvre et al. (2007) Freshwater 0.6 DQ244034 DQ244020 DQ244035 DQ244037 DQ244038 Lepère et al. (2007) Freshwater 5 Lepère et al. (2008) Freshwater 0.2 No EF196778 EF196733 EF196689 Lefèvre et al. (2008) Freshwater 0.6 EU162630 EU162627 References Behnke A, Bunge J, Barger K, Breiner H-W, Alla V, Stoeck T (2006). Microeukaryote Community Patterns along an O2/H2S Gradient in a Supersulfidic Anoxic Fjord (Framvaren, Norway). Appl Environ Microbiol 72: 3626-3636. Countway PD, Gast RJ, Savai P, Caron DA (2005). Protistan diversity estimates based on 18S rDNA from seawater incubations in the Western North Atlantic. J Eukaryot Microbiol 52: 95-106. Dalby AP, Kormas KA, Christaki U, Karayanni H (2008). Cosmopolitan heterotrophic microeukaryotes are active bacterial grazers in experimental oil-polluted systems. Environ Microbiol 10: 47-56. Diez B, Pedros-Alio C, Massana R (2001). Study of genetic diversity of eukaryotic picoplankton in different oceanic regions by small-subunit rRNA gene cloning and sequencing. Appl Environ Microbiol 67: 2932-2941. Edgcomb VP, Kysela DT, Teske A, de Vera Gomez A, Sogin ML (2002). Benthic eukaryotic diversity in the Guaymas Basin hydrothermal vent environment. Proc Natl Acad Sci U S A 99: 7658-7662. Lefèvre E, Bardot C, Noel C, Carrias JF, Viscogliosi E, Amblard C et al (2007). Unveiling fungal zooflagellates as members of freshwater picoeukaryotes: evidence from a molecular diversity study in a deep meromictic lake. Environ Microbiol 9: 61-71. Lefèvre E, Roussel B, Amblard C, Sime-Ngando T (2008). The Molecular Diversity of Freshwater Picoeukaryotes Reveals High Occurrence of Putative Parasitoids in the Plankton. PLoS ONE 3: e2324. Lefranc M, Thenot A, Lepere U, Debroas D (2005). Genetic diversity of small eukaryotes in lakes differing by their trophic status. Appl Environ Microbiol 71: 5935-5942. Lepère C, Domaizon I, Debroas D (2007). Community composition of lacustrine small eukaryotes in hyper-eutrophic conditions in relation to top-down and bottom-up factors. FEMS Microbiol Ecol 61: 483-495. Lepère C, Domaizon I, Debroas D (2008). Unexpected Importance of Potential Parasites in the Composition of the Freshwater Small-Eukaryote Community. Appl Environ Microbiol 74: 2940-2949. Lopez-Garcia P, Philippe H, Gail F, 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. Lovejoy C, Massana R, Pedros-Alio C (2006). Diversity and Distribution of Marine Microbial Eukaryotes in the Arctic Ocean and Adjacent Seas. Appl Environ Microbiol 72: 3085-3095. Massana R, Balague V, Guillou L, Pedros-Alio C (2004). Picoeukaryotic diversity in an oligotrophic coastal site studied by molecular and culturing approaches. FEMS Microbiol Ecol 50: 231-243. Richards TA, Vepritskiy AA, Gouliamova DE, Nierzwicki-Bauer SA (2005). The molecular diversity of freshwater picoeukaryotes from an oligotrophic lake reveals diverse, distinctive and globally dispersed lineages. Environ Microbiol 7: 1413-1425. Slapeta J, Moreira D, Lopez-Garcia P (2005). The extent of protist diversity: insights from molecular ecology of freshwater eukaryotes. Proc R Soc Biol Sci Ser B 272: 20732081. Zuendorf A, Bunge J, Behnke A, Barger KJA, Stoeck T (2006). Diversity estimates of microeukaryotes below the chemocline of the anoxic Mariager Fjord, Denmark. FEMS Microbiol Ecol 58: 476-491.