Physiological response data of different Amphistegina spp. to thermal stress

We compared the responses of large benthic foraminifera to thermal stress in specimens from a population of Amphistegina lessonii, an abundant Indo-Pacific species, to specimens of A. gibbosa, its Atlantic counterpart, from a similar environment but two different water depths (5 m and 18 m). The test groups were exposed in a common experiment to three thermal-stress scenarios over a four-week period: (a) no thermal stress, i.e., control conditions at constant 25.5°C; (b) a single thermal stress event up to 32°C for three days, followed by control conditions; (c) episodic thermal stress events alternating with periods of six days at control conditions, and (d) chronic thermal stress at 32°C. Growth, respiration, mortality, and motility were measured to characterize the holobiont response. Coloration, photosynthesis, and chlorophyll a content were measured to determine the response of the endosymbiotic diatoms.