Thermal biology and plasticity of the thermal metabolic scope of angel fish Pterophyllum scalare acclimated to different temperatures

Abstract

The angelfish Pterophyllum scalare ornamental species from continental waters has economic importance due to its diversity and color patterns. Because this fish is sensitive to environmental changes and handling conditions, knowing its thermal biology is vital to provide optimal conditions for its management and use in aquaculture. This study determines the thermal tolerance, window width, and thermal metabolic scope (TMS) in angelfish juveniles acclimated at 20, 24, 28, and 32 °C temperatures. The thermal window width calculated for P. scalare was 269 ºC2. The thermal metabolic scope obtained in animals acclimated at the interval 20-32 °C (P < 0.05) had the maximum efficiency value of 1026.0 (mg O2 h-1 kg-1w.w) at 28 °C, which coincides with the preferred temperature. The results showed that the metabolic rate decreased at the lowest and highest acclimation temperatures. To conclude, integrating all the data, this fish species is eurythermal tropical, based on its thermal window and compared to other cichlids. Therefore, the present research study contributes to the knowledge of thermal biology of organisms that can be applied to management plans of aquaculture farms for their maintenance and care.