INFLUENCE OF BIOFLOC MEAL ON THE GROWTH PERFORMANCE OF PACIFIC WHITE SHRIMP, Litopenaeus vannamei

Title Influence of biofloc meal on the growth performance of pacific white shrimp, Litopenaeus vannamei Name of the Student P.Ruby, B.F. Sc, Degree M.F. Sc Chairman Dr. S. Athithan Department Department of Aquaculture College Fisheries College and Research Institute, Thoothukudi – 628 008 Year and University 2017 / Tamil Nadu Fisheries University The present study was undertaken with an objective of evaluating the effect of dry biofloc meal on growth performance of Litopenaeus vannamei fed with different inclusion levels of dry biofloc meal such as 20 % (T1), 30 % (T2), 40 % (T3), 50% (T4), 50 % commercial shrimp feed & 50 % wet biofloc (T5) and Commercial shrimp feed (C). Juvenile were fed with different experimental feeds, thrice a day, at the rate of 8.1 2.3 % based on the total body weight. The experiment was conducted for a period of 60 days. During the experimental period, water samples were analyzed at weekly interval for their physico-chemical characteristics such as temperature, dissolved oxygen, salinity, pH, alkalinity, ammonia, nitrite and nitrate. After 60 days, higher weight gain was recorded in commercial feed (C 11.55 g) followed by 20 % inclusion level of dry biofloc meal (T1 10.76 g), 30 % dry biofloc meal (T2 10.26 g), 50 % commercial shrimp feed & 50 % wet biofloc (T5 10.06 g), 40 % dry biofloc meal (T3 9.18 g) and 50 % dry biofloc meal (T4 7.8 g). Higher average daily growth, higher specific growth rate, lower FCR, higher feed conversion efficiency, higher feed efficiency ratio and higher protein efficiency ratio were recorded in the juvenile, which were fed with commercial feed (C) followed by 20 % dry biofloc meal (T1), 30 % dry biofloc meal (T2), 50 % commercial shrimp feed & 50 % wet biofloc (T5), 40 % dry biofloc meal (T3) and 50 % dry biofloc meal (T4). The mean weight gain of Litopenaeus vannamei juvenile reared in seawater showed highly significant positive correlation (p < 0.001) with different inclusion level of dry biofloc and wet biofloc in the experimental diets. Student‘s ̳t‘ test confirmed that mean growth value of Litopenaeus vannamei juvenile reared in seawater fed with different experimental diets showed significance differences (p < 0.05) between T1 & T2 (P < 0.01), T2 & T4 (p < 0.04), T3 & C (p < 0.01), T4 & C (p < 0.02) and T1 & T4 (p < 0.02), but, not between T1 & T3, T1 & T5, T1 & C, T1 & T3, T2 & T5, T2 & C, T3 & T4, T3 & T5, T4 & T5 and T5 & C. One way ANOVA of the data clearly affirmed that between different experimental diets and sampling periods, Litopenaeus vannamei juvenile reared in seawater had significant difference (p < 0.05) among the different experimental diets. Further, as per the Duncan Multiple Range Test, it was inferred that mean growth value of Litopenaeus vannamei juvenile reared in seawater fed with different experimental diets showed significant difference (p < 0.05) among the diets. From this study, it was concluded that between the different inclusion levels of dry biofloc supplementation and control diet tested, control diet (commercial shrimp feed C) exhibited highest growth followed by T1 (20 % dry biofloc meal), T2 (30 % dry biofloc meal), T5 diet (containing 50 % commercial feed & 50 % wet biofloc), T3 (40 % dry biofloc meal) and T5 (50 % dry biofloc meal). Among the different inclusion levels of dry biofloc meal diets tested, 20 % inclusion (T1) showed better growth rate than other inclusion levels. Apparently, among the different test diets tested (T1, T2, T3, T4, T5 and C), no significant differences were observed between C & T1, C & T5 and T1 & T5. Although Control diet (commercial shrimp feed) showed higher growth rate than T5 diet (50 % commercial shrimp feed & 50 % wet biofloc) and T1 (20 % dry biofloc meal), considering the relative growth performance and cost of the feed, T5 & T1 diets could be considered for the culture of Litopenaeus vannamei.