Thermal acclimation capacity and standard metabolism of the Pacific white shrimp Litopenaeus vannamei (Boone, 1931) at different temperature and salinity combinations

In aquatic environments, rising temperatures reduce the oxygen content of the water while increasing the oxygen demand of organisms. In intensive shrimp culture, it is of great importance to know the thermal tolerance of cultured species and their oxygen consumption since this affects the physiological condition. In this study, the thermal tolerance of Litopenaeus vannamei was determined by dynamic and static thermal methodologies at different acclimation temperatures (15, 20, 25, and 30 degrees C) and salinities (10, 20, and 30 ppt). The oxygen consumption rate (OCR) was also measured to determine the standard metabolic rate (SMR) of shrimp. Accli-mation temperature significantly affected the thermal tolerance and SMR of Litopenaeus vannamei (P < 0.01). Salinity had a large effect on SMR (P < 0.01) but did not influence the thermal acclimation of the shrimp (P > 0.01). Litopenaeus vannamei is a species that has high thermal tolerance and can survive at extreme temperatures (CTmin-CTmax: 7.2-41.9 degrees C) with its large dynamic (988, 992, and 1004 degrees C2) and static thermal polygon areas (748, 778 and 777 degrees C2) developed at the above temperature and salinity combinations and resistance zone (1001, 81 and 82 degrees C2). The optimal temperature range of Litopenaeus vannamei is the 25-30 degrees C range, where a decrease in standard metabolism is determined with increasing temperature. Given the SMR and optimal temperature range, the results of this study indicate that Litopenaeus vannamei should be cultured at 25-30 degrees C for effective production.