Combined effect of body weight, temperature and salinity on shrimp Litopenaeus vannamei oxygen consumption rate

Aiming to optimize the calculations of mechanical aeration requirements in Litopenaeus vannamei marine shrimp cultures, oxygen consumption was quantified in combined conditions of temperature (20, 25 and 30ºC) and salinity (1, 13, 25 and 37 ‰) at three body weights (2, 6 and 12 g) for juvenile L. vannamei. To measure oxygen consumption, shrimps were placed in a semi-open respirometry system. Results demonstrate that temperature, salinity, shrimp size and the interaction of these parameters significantly influence the specific oxygen consumption (mg O2 g-1 h-1). The 2-g shrimp perhaps suffered osmotic stress and consumed more oxygen at salinity 37 ‰, whereas 6 and 12-g shrimp suffered such stress at salinity 1 ‰. At 25 and 30ºC oxygen consumption was more stable at salinities 13 and 25 ‰ for all groups. At 20ºC and salinity below 25 ‰ oxygen consumption was higher, possibly due to the reduced hyperosmoregulatory ability in lower temperatures. The resulting regression equations allowed the calculation of L. vannamei shrimp oxygen consumption at the temperatures, salinities and sizes tested in this study. The equations can be used for the estimation of the environmental capacity and also the mechanical aeration requirements to secure ideal levels of oxygen in L. vannamei culture systems.