Effects of salinity fluctuation on the growth and energy budget of juvenile litopenaeus vannamei at different temperatures

Abstract

The effects of salinity fluctuation on the growth, molting and energy budget of juvenile Litopenaeus vannamei was investigated at the temperatures of 20, 25, and 30°C. Salinity fluctuation regimes were set in different amplitudes of ± 0, ± 5, ± 10 and ± 15 gL -1 from a control salinity of 20 gL-1. After a 48-day feeding trial, the lowest survival occurred at a salinity fluctuation of ± 15 gL-1 for each temperature investigated. The best growth of shrimp was obtained at salinity amplitudes of ± 5-10 gL-1 at 25 and 30°C. The salinity fluctuation influenced food conversion efficiency but not food intake. The shrimp maintained at salinity amplitudes of ± 5-10 gL-1 expended most of the energy for growth and spent less energy on respiration and excretion at 25 and 30°C. Therefore, salinity fluctuating amplitudes of ± 5-10 gL-1 result in higher growth rates than constant salinity conditions (20 gL-1) through enhanced feed assimilation and reduced energy loss in respiration and excretion. © The Crustacean Society.