Ionic manipulation of inland saline groundwater for enhancing survival and growth of Penaeus monodon (Fabricius).

A series of four trials were conducted on inland saline groundwater of 58 g L−1 diluted to lower salinities up to 10 g L−1 and later manipulating its ionic concentrations to enhance the survival and growth of Penaeus monodon postlarvae (PL). In the first experiment, the survival of PL was tested at several salinities (10, 20, 30, 40, 50 and 58 g L−1), and the survival of PL was studied in comparison with natural sea water of similar salinities. Complete mortality of PL was observed at all salinity levels within 144 h. Longest survival for 96 h followed by 72 h was found at 10 and 20 g L−1 salinity respectively. In the second experiment, survival of PL was tested at 10–20 g L−1 salinity at different concentrations of calcium varying between 100 and 300 mg L−1. The survival of PL could be increased to 7 days at 12.5 g L−1 salinity by reducing the calcium level to 200 from 921.8 mg L−1 with magnesium and potassium levels of 208.5 and 30.03 mg L−1 respectively. In the third experiment, the survival of PL could be further enhanced to 18 days at the same salinity by increasing the magnesium level from 208.5 to 400 mg L−1 with potassium held at 30.03 mg L−1. Survival and growth of PL in inland saline water of 12.5 g L−1 salinity similar to performance in sea water of the same salinity was achieved by increasing the potassium concentration from 30.03 to 200 mg L−1 with calcium and magnesium levels of 199.5 and 199.4 mg L−1 respectively. [ABSTRACT FROM AUTHOR]