File:41467 2023 40657 Fig1.webp

English: Examples of protists highlighting the morphological diversity of extremophiles. a Frontonia sp., an alkaliphilic ciliate from soda lakes in Kenya. Light microscope image courtesy of Geoffrey Odhiambo Ong’ondo (Egerton University). b Chlamydomonas pitschmanii Ettl, a strain of thermoacidophilic green algae isolated from hot spring soils. Light microscope image courtesy of Antonino Pollio (University of Naples Federico II). c Tetramitus thermacidophilus strain BSL, an amoeboflagellate from an acidic geothermal lake (Boiling Springs Lake) at Lassen Volcanic National Park in northern California, USA. DIC image courtesy of Gordon Wolfe (California State University, Chico), photographed by Billie Reeder. d Galdieria sulphuraria, a mixotrophic species of thermoacidophilic red algae, here growing under illumination. Light micrograph courtesy of Gerald Schöenknecht (Oklahoma State University, Heinrich-Heine-Universität Düsseldorf). e Halocafeteria seosinensis, a halophilic, heterotrophic nanoflagellate isolated from a saltern in Korea. SEM image courtesy of Jong Soo Park (Kyungpook National University).