Effect of temperature and salinity on the oxygen consumption of laboratory produced Penaeus vannamei postlarvae

Abstract

The routine rate of oxygen consumption by Penaeus vannamei postlarvae (mean weight = 0.15 g) was determined at four temperatures and five salinities. The time course of oxygen depletion in the chambers was independent of the dissolved oxygen (DO) level down to 1.3 mg/1. Oxygen consumption during normoxic conditions increased with temperature and ranged from 0.0060 mg/g/min at 25 ppt and 20°C, to 0.0183 mg/g/min at 35 ppt and 32°C. Salinity had only a marginal effect on consumption. At high salinities, there was an increase in the metabolic demand, probably caused by an apparent loss in the capacity to maintain the osmotic and ionic balances as temperature increased. A critical point (Pc), where oxygen consumption by the shrimp changes from being independent of DO level to being dependent, was found. Pc was correlated to temperature. Below Pc, oxygen consumption was reduced to approximately 34% of the normal rate.