EXPLORATION OF DIFFERENT CARBON SOURCES ON MICROBIAL BIOFLOC PRODUCTION, GROWTH AND BODY INDICES OF Pangasianodon hypophthalmus

A 90 day experiment was conducted to investigate the production of microbial floc using four different carbon sources and its effect on growth and body indices of Pangasianodon hypophthalmus with body weight of 6.4 ± 0.05 g. There were totally four experimental groups using carbon sources viz. Tapioca (BFT-T), sorghum (BFT-S), pearl-millet (BFT-PM) and finger-millet (BFT-FM) and one control (no addition of carbon sources). The carbon sources were added to different experimental tanks to establish a biofloc at carbon/nitrogen (C/N) ratio of 15:1. Growth was monitored at fortnight intervals, body indices were analysed at end of the experiment. Fishes reared under the groups of different carbon sources added displayed higher Daily increment( DI), specific growth rate (SGR), and daily growth index (DGI) than control (CW) groups (P<0.05).  Feed conversion ratio (FCR),) was improved in the all BFT treatment groups when compared to clear water treatment. Body indices like hepato-somatic index (HIS) and viscera-somatic index (VSI) were not significantly influenced by different carbon sources used in this study. Significantly highest floc volume was observed BFT-FM treatment groups .Based on the results, finger-millet could be used as a best carbon source to yield high amounts of microbial biofloc and to improve the growth performance of P. hypophthalmus .