Effects of temperature and salinity on growth and feed utilization of giant freshwater prawn(Macrobrachium rosenbergii)

Abstract

The study aims to evaluate the combined effects of salinity and temperature on growth and feed utilization of giant freshwater prawn to contribute for development the prawn farming under the impact of climate change in the Mekong Delta of Vietnam. The experiment was conducted with two factors. The first factor was the temperature - ambient temperature (not adjusted); 31ºC and 34ºC (using heater). The second factor was salinity at 3 levels of 0‰; 5‰ and 10‰. The experiment consisted of 9 treatments and each treatment was triplicated. The treatments were randomly designed. Prawn were stocked at a density of 14 inds/tank with male : female ratio of 1:1 (7 males and 7 females) and each were kept separately in a cylindrical plastic cage. The results showed that the growth performance of prawns was effected by temperature (p<0.05). The best growth performance was found at the treatments with ambient temperature at 0‰, 5‰ and 10‰ and they were significantly different (p<0.05) compared to the other treatments. The treatments with 34ºC - 0‰; 5‰ and 10‰ had the lowest growth and they were not significantly different (p>0.05) compared to the treatments at 31ºC. Feed efficiency was also affected by temperature, treatment with ambient temperature (0‰; 5‰ and 10‰) that had the lowest FCR and the highest PER which was significantly different from other treatments (p<0.05). The survival rate was significantly affected by salinity (p<0.05). The survival rate was highest in the treatment 5‰ salinity which was significantly different compared to the treatments 0‰ and 10‰ salinity (p<0.05).