Acute thermal tolerance of two Antarctic copepods, Calanoides acutus and Calanus propinquus

Abstract 1. 1. The thermal tolerance of Antarctic copepod species Calanoides acutus and Calanus propinquus was tested with a short-term exposure (15 min) at three constant temperatures of 14, 16 and 18°C and after 12-h exposure at three constant temperatures of 14, 15 and 16°C. 2. 2. Lethal temperatures (LT 50 ) after an exposure time of 15 min and a recovery time of 30 min were 18.1°C for C. acutus and 16.1°C for C. propinquus . In 12 h exposure LT 50 for C. acutus was 14.3°C. 3. 3. The results give support to some recent observations that at least in short-term exposure Antarctic copepods exhibit a higher tolerance for elevated temperatures than suggested before for Antarctic marine poikilotherms.