Abstract

The clownfish Amphiprion ocellaris is widely distributed in the coral reef ecosystems of tropical and subtropical regions of the West Indo Pacific, an area that hosts economically valuable species, and, thus, a suitable candidate for warm water aquaculture. This study determined the preferred temperature, critical threshold limits, represented by critical thermal maximum and critical thermal minimum, thermal window width, and aerobic metabolic scope of A. ocellaris clownfish acclimated to 20, 23, 26, 29, 32, and 35 degrees C. A positive response (P0.05) occurred when the preferred temperature significantly increased with increasing acclimation temperature. The preferred temperature obtained graphically was 30.0 degrees C. Acclimation temperature significantly affected the thermal tolerance which increased with acclimation temperature. The thermal window calculated for A. ocellaris was 301.5 degrees C-2. The thermal metabolic scope obtained in animals acclimated at the interval from 23 to 32 degrees C (P>0.05) had a mean value of 4240.8mg O(2)h(-1)kg(-1)w.w., revealing that A. ocellaris is a eurythermal species with a range of optimal physiological performance that closely matches the environmental conditions where it can be farmed. Therefore, the highest value of the thermal aerobic scopes corresponded to the intervals of the preferred temperature obtained for A. ocellaris. These results may partially explain their worldwide distribution pattern, as well as their aquaculture potential in tropical regions.