Thermal preference and tolerance of Peruvian grunt Anisotremus scapularis juveniles (Pisces: Haemulidae)

Thermal preference and tolerance of juvenile Anisotremus scapularis (Pisces: Haemulidae) at different acclimation temperatures (14, 17 and 22 degrees C) were evaluated in order to estimate the optimum temperature and the thermal tolerance limits of this species. The preference was determined through acute preferred temperature. Maximum critical temperature and mean lethal temperature allowed to estimate thermal tolerance. The results show that acclimation temperatures higher than 14 degrees C increase both thermal preference and tolerance. However, individuals acclimatized to 22 degrees C preferred temperatures lower than their acclimation. In addition, thermal tolerance was identical between individuals acclimatized at 17 degrees C and 22 degrees C. The optimum temperature of juvenile A. scapularis was 18.7 +/- 2 degrees C and its upper and lower tolerance limit was 32.6 and 10.1 degrees C, respectively. Based on the results, we concluded that a temperature of 18.7 +/- 2 degrees C would optimize the physiological processes in juvenile A. scapularis and that temperature higher than 32.6 degrees C and lower than 10.1 degrees C would cause the immediate death of the organism.