MASS PRODUCTION OF ROTIFER (BRANCHIONUSCALYCIFLORUS) FOR AQUACULTURE
Mass production of freshwater rotifer, Branchionuscalyciflorus was carried out using different food types (Chlorella sp., Spirulina sp., and Baker’s yeast). Rotifer stock culture was prepared using NPK + urea (50g: 2.5g) and chicken droppings with freshly grown alga. Different food concentrations (150, 300, 650 and 1000 mg/ml) and feeding intervals (2x and 3x per day) were used to grow B. calyciflorus in a Batch culture method. Optimum pH (7.02±0.06), dissolved oxygen (6.68±1.23 mg/l) and temperature (26.00±0.02 °C) were maintained in the course of the experiment. Rotifers were sampled every two days to determine the population and counting of the population was done using calibrated petri-dish wider stereomicroscope. Number of rotifers was expressed in individual/ml. Data obtained showed that there was significant difference in population growth increase in all the variables used in this study (P < 0.05). The highest population growth was attained with 650 mg/ml of Chlorella sp. (213.81±9.94 individuals/ml), followed by Baker’s yeast (196.67±8.18 individuals/ml) and 300 mg/ml of Spirulina sp. (151.90±7.98 individuals/ml). The least population growth of B. calyciflorus was recorded with 150 mg/ml concentration of Chlorella sp. and Spirulina sp. (81.43±6.19 and 75.71±5.12 individuals/ml, respectively), and 1000mg/ml of Baker’s yeast (65.r24 ±3.86 individuals/ml). Generally, higher food concentrations (1000 mg/ml and 650 mg/ml) did better with 2x feeding interval (90.16±3.47 and 176.19±9.57 individuals/ml) respectively (p < 0.05). The lower concentrations (150mg/ml and 300mg/ml) gave the best population growth of B. calyciflorus with 3x feeding interval. The peak population growth was attained on day 8 of the experiment (p < 0.05). The present study indicated that the quantity and quality of food have a significant role on the rotifer production and Chlorella sp. at 650 mg/ml appears most suitable to feed rotifers for maximal production.