EFFECT OF STOCKING DENSITY ON GROWTH AND SURVIVAL IN INDIAN RIVER PRAWN MACROBRACHIUM MALCOLMSONII (H MILNE EDWARDS)

摘要

Effect of stocking density on growth and survival in Macrobrachium malcolmsonii was studied in six earthen tanks of size 0.02ha each at Central Institute of Freshwater Aquaculture, Kausalyaganga Farm. The advanced post larvae with an average weight of1.02g were stocked at 1 (T-l), 2 (T-ll) and 3 (T-lll) PL / nr2. Rearing was carried out for 180 days. PL were fed twice a day with commercial diet having 42% protein and 6% lipid @ 7- 10% of the body weight. Growth increment was recorded fortnightly. The water quality parameters monitored periodically were found within the desired ranges. Data manifested significantly higher (p< 0.05) growth rate in prawns in T-l compared to T-ll and T-lll. Average final growth was 47.1g, 32.4g and 18.35g in treatmentT-l, T-ll and T-lll tanks respectively. Similar trend was also noticed in the survival recording 81% , 65% and 40% in T-l, T-ll and T-lll respectively. Specific growth rate (SGR) was computed to be highest 0.88% in T-l followed by 0.79% in T-ll and 0.65%in T-lll stocking density. Results further suggest that although the average weight gain and survival were much higher in T-l, the total biomass production recorded to be insignificantly higher 8.42kg in T-ll compared to 7.63kg in T-l but significantly(p<0.5) much less 4.4kg in T-lll. The Feed Conversion ratio (FCR) was found to be lowest in T-l (1.82) followed by T-ll (2.36) and T-lll (2.94) suggesting suitable stocking density at 2-pQSt larvae/m2 for optimum prawn production.