EFFECT OF ACCLIMATION TEMPERATURES ON THE THERMAL LIMITS OF FRESHWATER ANGELFISH, PTEROPHYLLUM SCALARE

Abstract

This study aims to evaluate the effect of acclamation temperature on the thermal tolerance of fresh water angel fish Pterophyllum scalare. The temperature variation given to juveniles (0.3 to 0.49) were 26°C 28°C. 30°C, 32°C 34°C and the control at ambient temperature. The critical thermal maxima (CTMax) and critical thermal minimum (CTMin) of P. scalare was affected significantly by temperature variations. A direct relationship was obtained between the critical temperature and the acclimation temperature which increased at intervals of 1- 15°C. The end point of CTMax in the species was loss of swimming balance. The critical thermal limit (CTmax and CTmin) was found to be within 16°C-44°C.