Maximum critical temperature and oxygen consumption during thermoregulation in Macrobrachium americanum (Bate, 1868) adult prawns

Macrobrachium americanum is a large prawn living in rivers and coastal water bodies of tropical and subtropical ecosystems of the Pacific side of the Americas. Water temperature and salinity are the main physicochemical variables determining its distribution. Temperature also influences its metabolic rate, which determines growth rate and reproduction. Because of this, preferred temperature, critical thermal maximum (CTMax), and O2 consumption rates at four temperatures (20, 24, 28, and 32°C) were tested from wild prawns in laboratory assays. Those temperatures correspond to the annual temperature fluctuations at the sampling site. The final preferred temperature of this species is close to 26.4°C. The acclimatization temperature has an almost linear effect on the CTMax (R2 = 0.987, P < 0.05), and the oxygen consumption routine rates increased as the acclimation temperature increased from 20 to 32°C.