The critical thermal maxima (CTMax) of Farfantepenaeus aztecus was not affected significantly by salinity (P > 0.05). A direct relationship was obtained between the critical temperature and the acclimation temperature which increased at intervals of 3-5 degrees C. The end point of CTMax in F aztecus was loss of righting response (LRR). The acclimation response ratio (ARR) for the juveniles of the brown shrimp ranged between 0.20 and 0.80, which agreed with others obtained for crustaceans from tropical and subtropical climates. The brown shrimp should not be exposed to conditions that cause total disorientation
if this is avoided, it will permit an increase in growth and reduce mortalities in culture populations. (c) 2005 Elsevier Ltd. All rights reserved.