Study on Biofloc Characteristics, Digestive Enzyme Activity and Physiological Responses in Polyculture Model Penaeus vannamei and GIF Tilapia (Oreochromis niloticus) Culture System-BFT Aquaculture System

Abstract

Background: The present study was undertaken to investigate the efficiency of biofloc on the floc characteristics, digestive enzyme activity, immunological responses and haemato-biochemical parameters for the production of Penaeus vannamei and Genetically Improved Farmed Tilapia in a polyculture model. Methods: Four lined pond were used following completely randomized design using biofloc and clear water culture systems. Each lined pond (12 m × 10 m × 1.5 m) was stocked with 60 shrimp/m3 of P. vannamei (1.06±0.08 g) and 5 no’s/m3 of GIF tilapia (0.42±0.01 g) and reared for 90 days. Biofloc was developed and maintained using soya pellet powder as carbon source and vigorous aeration was provided to keep floc in suspension. Result: The study found significantly higher TS (1167.50±78.50 mg/L), TSS (434.05±62.90 mg/L) and TDS (733.45±108.22 mg/L) were recorded in lined pond based biofloc system. Significantly higher digestive enzymes of protease (7.98±0.36 and 3.62±0.16 U/ mg protein/min), lipase (3.43±0.20 and 8.65±0.20 U/ mg protein/min) and amylase (1.35±0.10 and 3.25±0.17 U/mg protein/min) were recorded in P. vannamei and GIF tilapia in lined pond based biofloc culture system, respectively. The study found significantly improved immunological responses of prophenol oxidase activity (71.25±1.28 µmol.min-1.ml-1), total haemocyte count (4.75±0.12 × 106 cells/ml) and catalase activity (3.56±0.03 Units/ml) in biofloc cultured P. vannamei. Higher values of RBC (1.95±0.05 million/cu mm), WBC (49.65±1.56 1000/cu mm), hemoglobin (9.21±0.15 g/dl), hematocrit (33.42±0.89%), albumin (1.18±0.04 g/dl), globulin (4.39±0.16 g/dl), total protein (5.58±0.14 g/dl) and total cholesterol (9.32±0.41 g/dl) were recorded in GIF tilapia reared in biofloc culture system. Therefore, the study suggests that polyculture model of P. vannamei and GIF tilapia in biofloc culture system improves the physiological performance and production augmentation.