Center: Detail of a microbial mat located at one of the saltern ponds in Salins de Giraud, La Camargue, Rhône Delta, France (04º 11’ E–04º 51’ E; 43º 40’ N–40º 47’ N). The photograph shows the broken upper layer of a drying mat. Photograph by Mercedes Berlanga (University of Barcelona, Spain). (Scale, ca. 0.22×)

Upper left: Several virions of the lymphocystis virus, family Iridoviridae. Virus particle size is around 350 nm. The virus was isolated from the fish Sparus aurata (seabream). Negative staining transmission electron micrograph by Enric Ribes, Rosa M. Pintó and Albert Bosch (University of Barcelona, Spain). (Magnification, ca. 34,200×)

Upper right: Scanning electron micrograph of Carnimonas nigrificans strain CTCBS1. The strain was isolated by Margarita Garriga (IRTA-Meat Technology Centre, Girona, Spain), who also performed the microscopy. (Magnification, ca. 9600×)

Lower left: Bright-field light micrograph of the thermotolerant photosynthetic euglenoid Euglena pailasensis, isolated from an acidic hot mud pool at Las Pailas, near the Rincón de la Vieja volcano, Guanacaste, Costa Rica. This strain –the most thermotolerant euglenoid described so far, and the first reported to inhabit acidic hot aquatic habitats– was isolated and photographed by Ana Sittenfeld (University of Costa Rica, San José, Costa Rica) and Aurelio Serrano (Institute of Plant Biochemistry and Photosynthesis, CSIC-University of Sevilla, Spain). (Magnification, ca. 2000×)

Lower right: Halophilic black yeast Phaeotheca triangularis from the hypersaline water of Secovlje saltern along the Adriatic coast, Slovenia. Interference contrast micrograph by Polona Zalar (University of Ljubljana, Slovenia). (Magnification, ca. 1000×)