Combined influence of temperature and salinity on oxygen consumption of the larvae of the pink shrimp, Palaemon serratus (Pennant) (Crustacea, Decapoda, Palaemonidae)

The oxygen consumption of the six successive zoeal stages of Palaemon serratus reared in 30 different combinations of temperature and salinity was measured. Oxygen consumption per individual, R, increased with the age (or the dry weight, W) of the larvae according to a power function R= a· W b , but no significant relationship was found between the specific respiration, R′ (respiration rate per dry weight unit), and the dry weight of successive larval stages. Nevertheless, highest rates were always observed in the ZIV, for all temperature and salinity conditions. These maxima were probably related to large nutritional changes occurring at this period of development. Temperature affected R′ according to a linear function R′ = a′ + b′· T. Q 10 values varied between 1.50 and 2.58 according to the larval stage and the salinity, except for the ZI at the lowest salinity where a very high value of 5.89 was recorded. The respiration rate decreased at the lowest and highest salinity values. The salinity effect on metabolic rates is described by a quadratic equation R′ = a″+ b″· S+ c· S 2. The combined effect of temperature and salinity on the respiration of the six successive larval stages is illustrated using tridimensional models. Maximal respiration rates were recorded at salinities between 25‰ and 31‰ and at the highest temperature (29°C).