Farm level feeding and production response of pacific white shrimp (Penaeus vannamei) in periphyton based farming system

Study on feeding and production response of Penaeus vannamei in periphyton based farming system was done at two farm levels, one at Certitude Shrimp Farm, Vetaikaranirrupu Nagapattinam and second at TST Aqua farm, Karuvelankadai, Nagapattinam in Tamil Nadu state of India. Growth and feed consumption pattern of trial and the control ponds were recorded every week from 37 days of culture (DOC) to 108 DOC. Trial pond was harvested at 108 DOC with an average body weight (ABW) of 33 g, with a total production of 4, 700 kg. In control pond, the total production was 3, 750 kg with an ABW of 26.8 g. During the first week immersion period in the pond, the substrates (split bamboos of 1.5 inch thickness and 3 feet height, tied together at 1 meter interval, to a length of 20 meter and erected continuously with 1.5 meter gap in 0.5 ha trial pond) were observed with formation of slimy biofilm over the substrate and after two weeks the growth of periphyton was observed over the substrate colonized by diatoms, green algae, blue green algae and copepods. The weekly feed consumption pattern was also less by 15 to 20 percent in trial pond during the culture period compared with the control pond. The trial pond (1: 1.22) has proven a better food conversion ratio (FCR) compared to control pond (1: 1.35). This farm level study has illustrated that the periphyton developed in Penaeus vannamei culture pond serve as natural food. Hence, periphyton growth on substrate serve as natural food source, thus reduces the intake of supplementary feed, also maintains good water quality, favors fast growth in Penaeus vannamei with good FCR and maintains good health condition.