Effect of Stocking Density of Labeo rohita (Rohu) for the Production of Stunted Yearling in Cage Culture Conditions

The present experiment evaluated the Optimization of Labeo rohita (Rohu) stocking density for the production of stunted yearling in cage culture conditions. Fingerlings were stocked at three different stocking densities i.e., 100, 200 and 300 (T1, T2, and T3, respectively) and reared for 180 days in cage culture condition. Water quality and growth parameters of all treatments were compared during the experiment. A significant (p<0.05) decrease in growth and survival concentration relative to the higher stocking density was observed. Though some of the parameters showed significant (p<0.05) differences among the treatments, the water quality remained within an optimum level, throughout the experiment. An increase in stocking density led to a significant reduction (p<0.05) in ABW and survival of fingerlings. Treatment T1 (100 nos/cage) recorded significantly higher growth than treatment T2 (200 nos/cage) and treatment T3 (300 nos/cage) of both locations during all the years. Among the treatments, T1 recorded significantly higher values of body weight (38.12 g) as compared to T2 (30.87 g) and T3 (27.19 g) but treatment T3 (27.19 g) was at par with T2 (30.87 g). Treatment T1 recorded higher average body weight at both locations during all the years 2013-14 (L1-31.30g and L2-35.98g), 2014-15 (L1-30.91 g and L2- 60.23 g) and 2015-16 (L1-26.37 g and L2-43.93 g) as well as in pooled results (L1-29.53 g and L2-46.72 g) as compared to rest of the treatments. The fish survival data revealed that at both locations and during all the years, there was little variation. As per the survival rate in different treatments, T3 is found most economical.