Temperature and salinity optima for growth and survival of juvenile banana prawns Penaeus merguiensis

Abstract

The growth and survival of juvenile Penaeus merguiensis (mean carapace length of 4 to 12 mm) were examined in a factorial combination of five temperatures (15, 20, 25, 30 and 35°C) and five salinities (5, 20, 35, 45 and 55%). The prawns were kept individually and examined daily for exuviae. Temperature, salinity and prawn size all affected the rate of growth. Salinity and size effects were expressed mainly through changes in the moult increment, while temperature influenced both the moult increment and the intermoult period. The optimum temperature and salinity for growth in length were 31°C and 30%. However, the highest rate of survival, as well as greatest increases in wet and dry weight, protein, fat and energy value per mm carapace length, occurred at a much lower temperature and salinity combination (20 °C and 20%). Taking both survival and growth into account, this resulted in an optimum temperature and salinity for the greatest increase in biomass and production of 28°C and 25%. Deviations from the optimum temperature have a greater effect on productivity than deviations from the optimum salinity.