Culture of freshwater prawns, Macrobrachium rosenbergii, in inland saline water ATUL KUMAR JAIN, GIRISH KUMAR AND K.D. RAJU1 There is growing interest around the world in utilizing inland saline water for aquaculture (Forsberg et al. 1996, Allan et al. 2001, Ingram et al. 2002, Samocha et al. 2002, Jain et al. 2004). The major ionic constituents of inland saline groundwater are similar to those in seawater but with different concentrations (Table 1). Inland saline groundwater is most commonly deficient in potassium and has an excess of calcium (Fielder et al. 2001). Potassium deficiency affects the survival of Penaeus rnonodon in inland saline water. Success could be achieved in culturing P rnonodon in inland saline water by fortifying the culture medium with potassium salts (Collins and Russell 2003, Rahman 2003). Macrobrachiurn rosenbergii is a freshwater palaemonid shrimp that completes the larval phase of its life cycle in seawater of 12 ppt (Ling 1967). However, the postlarvae (PL) and juveniles of M. rosenbergii survive in brackish water of 25 ppt salinity and exhibits good growth at 20 ppt (Sandifer et al. 1975). Commercial culture of M. rosenbergii can be conducted in coastal brackish water of low salinFigure 1. Wakoo/ Tullakool subsurface drainage scheme, NSW, Australia. (Photo by Atul Kumar Jain) ity (Karim 1996). Stern et al. (1987) studied the os- Table 1. motic and ionic regulation of M. rosenbergii using brackish water in an inland arid region in Israel but opined that growth and development were reduced Ions in water of exotic salinity and in which the ionic ratios differed markedly from those found in sea- Sodium water. A trial was performed to study survival and growth of M. rosenbergii in inland saline groundwater of 8-11 ppt at the village of Dhurmai, District Bharatpur, Rajasthan, India. A newly constructed earthen pond of 0.25 ha (Figure 1) was Magnesium Calcium Potassium Chloride Sulfate Concentration of major ions in saline water (Bharatpur, Rajasthan) and sea water of 8 ppt salinity. Concentration (mg/L) Percentage of Saline water Sea water1 sea water 2900 2436 1 19.04 707.6 312.8 226.21 561 . 1 92.8 604.63 5 85.6 5.84 2485 4408 56.37 300 626.4 47.89 filled with saline water (Table 1) from an open well to a depth of 1.25-1.50 m. The pond was fertilized 1 Boyd and Thunjai (2003) with 2,500 kg of raw cow manure 15 days prior of stocking. The pond was stocked with 2,000 M. rosenbergii PL (average weight 0.800 ± 0.125 g) along with 4,000 young M. cephalus (average weight 0.184 ± 0.013 g) during March 2002. The animals were fed on a ration consisting of rice bran and ground nut oil cake mixed in equal proportions (protein 25-28 percent, carbohydrate 50 percent and fat 8 percent). Feeding was done twice daily at 0700 and 1800 hrs WORLD AQUACULTURE 1 1
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