Effects of stocking densityon growth and body composition of labeo bata (Hamilton, 1822) rearedin earthenpond

Abstract

The present study was carried out to the effects of stocking density on growth and body composition of Labeo bata(Hamilton, 1822). Fishes were reared in three selected pond of “Maa fish farm”, Nawabgonj, Dinajpur, Bangladesh for a period of 60 days wherein 250 fry decimal-1, 500 fry decimal-1, 750 fry decimal-1were set as the different stocking densities demarked as treatment T1, T2 and T3 respectively. Mean initial length and weight of the fries were same in all three treatments. Mean final length and weight of the experimental fish was 10.4 ± 0.095,10.2 ±0.112, 9.9 ± 0.098 cm and 13.1 ± 0.90, 11.37 ± 0.817, 9.87 ± 0.701 g, respectively in T1, T2 and T3.T1 showed the highest length and weight gain after harvesting (P<0.05). The specific growth rate (%) was found highest (4.25 ±0.139) in T1and lowest (3.77±0.144) in T3, survival rate (%) was found highest 77.92 in T1 and lowest 67.65 in T3. The specific growth rate showed significant differences (P<0.05) among the treatment. Mean (±SD) moisture content (%) was found highest (79.23±1.57) in T2 and lowest (75.16±1.04) in T1. Mean (±SD) crude protein content (%) was found highest (17.14±0.622) in T1 and lowest (16.75±0.354) in T2.Mean (±SD) crude lipid content (%) was found 3.94±0.140 in T1, 4.51±0.180 in T2, 4.36±0.185 in T3.The ash content (%) was found highest (2.16±0.076) in T2 and lowest (1.81±0.110) in T1. There were no significant variations (P>0.05) in the value of crude protein, content among the treatments. Where moisture, crude lipid and ash content showed significant differences (P<0.05) in T1 but were not significant differences (P>0.05) in T2 and T3. Production of fingerling was 2.512, 4.251, and 5.008 kg decimal-1respectively in T1, T2 and T3. Despite of this, consistentlyhigher net benefits were found in T2 and lowest in T1.Therefore, of the threestocking densities, 500 fry decimal-1 appear to be most suitable stocking density for nursing and rearing of bata fry andfingerlingswhich could be recommended to adopt. However, more trials are suggested to optimize the stocking density and feeding regime for better production performance.