Thermal tolerance of Litopenaeus vannamei (Crustacea: Penaeidae) acclimated to four temperatures

Abstract

Critical thermal minima (CTMin) and maxima (CTMax) values were determined for the Pacific white shrimp Litopenaeus vannamei post-larvae and juveniles at four different acclimation temperatures (15, 20, 25, and 30°C). The CTMin of shrimp at these acclimation temperatures were 7.82, 8.95, 9.80, and 10.96°C for post-larvae and 7.50, 8.20, 10.20, and 10.80°C for juveniles, respectively, at 1°Ch-1 cooling rate. The CTMax values were 35.65, 38.13, 39.91, and 42.00°C for post-larvae and 35.94, 38.65, 40.30, and 42.20°C for juveniles at the respective acclimation temperatures. Both acclimation temperature and size of the shrimp affected CTMin values of L. vannamei (P<0.01). Overall, juveniles displayed significantly lower CTMin values than the post-larvae (P<0.0001). However, the CTMax response by post-larvae and juveniles were not significantly different from each other and no interaction was determined between the acclimation temperature and development stage (P>0.01). The area of the thermal tolerance polygon over four acclimation temperatures (15, 20, 25, and 30°C) for the post-larvae of L. vannamei was calculated to be 434.94°C2. The acclimation response ratio (ARR) values were high ranging from 0.35 to 0.44 for both post-larvae and juveniles. L. vannamei appears to be more sensitive to low temperatures than other penaeid species and its cold tolerance zone ranged from 7.5 to 11°C. In successful aquaculture temperature must never fall below 12°C to prevent mortalities. Upper thermal tolerance is less of a problem as in most subtropical regions maximum water temperature rarely exceeds 34°C, but care should be given if shallow ponds with low water renewal rate are being used. © 2010 Elsevier Ltd.SUF2008BAP6This study was financed by the Research Fund of the University of Cukurova (Adana, Turkey) by project code number SUF2008BAP6