Fattening of the Ridged Swimming Crab, Charybdis Natator Herbst

Abstract

For fattening three different salinities were tried (20, 25 and 30 ppt). The weight gain of the crabs cultured in 30 ppt was (58.0 g) significantly higher than 20 (46.7 g) and 25 (50.4 g) ppt. The shell was becoming harder in shorter duration (10.6 days) when the water crabs were cultured in 30 ppt rather than other salinities (20 and 25 ppt). Hence 30 ppt was selected as optimum salinity for the culture of water crabs as evidenced by higher weight gain and shorter duration for shell hardening.The water crabs offered with trash fish showed a significantly higher weight gain (50.40 g). The crabs were hardened significantly in very shorter duration when they were fed with trash fish (14 days). However, the animals were taking longer duration when fed with clam (17.6 days) and oyster (16.6 days). The survival of the crabs was 100% irrespective of the feeds used. So trash feed is recommended as a best feed for fattening of C. natator.