Species found in the sampled cenotes in Cancun, Quintana Roo, Mexico A Euglena mutabilis B Euglena texta C Lepocinclis acus D Phacus sp. E Phacus orbicularis F Phacus longicauda G Dinobryon sertularia H Coscinodiscus radiatus I Amphora ocellata J Cyclotella meneghiniana K Oscillatoria limosa L Radiocystis geminata M Pseudanabaena mucicola N Merismopedia angularis O Aspidisca sp. P Vorticella sp. Q Paramecium aurelia F Coleps sp. S Arcella gibbosa T Amoeba radiosa U Mayorella vespertilioides. Scale bars: 10 µm.