EFFECTS OF SALINITY ON GROWTH AND RELATED INDICATORS OF GONADAL DEVELOPMENT IN EXOPALAEMON CARINICAUDA (DECAPODA, CARIDEA, PALAEMONIDAE)

To explore the effects of salinity on the growth and gonadal development of Exopalaemon carinicauda, shrimps were raised at five different levels of salinity (16, 20, 24, 28, 32) in a water environment. The growth, performance in ovarian development, ovarian nutrient concentration, as well as vitellogenin and sex hormone levels were measured. The results showed that the final body weight and specific growth rate of E. carinicauda increased at first and then decreased with increasing salinity (P <0.05), with the fastest growth occurring at salinity 24. The gonadosomatic index increased at first and then decreased with increasing salinity (P <0.05), with the highest index also occurring at salinity 24. The ovarian maturation rate of E. carinicauda was highest at salinity 28, and the concentration of total protein, total cholesterol, and triglycerides in the ovaries similarly increased at first until salinity 24, and then decreased with increasing salinity (P <0.05). Likewise, the concentration of vitellogenin in the hepatopancreas increased at first and then decreased with increasing salinity (P <0.05), with the highest concentration occurring at salinity 24. The concentration of estradiol in E. carinicauda ovaries was highest in the groups at salinities 24 and 28. These results show that salinity levels of 24-28 were the most suitable for promoting the maturation of parent shrimps, and thus would likely be optimal for industrial culturing.