An experimental trial was conducted for 90 days to evaluate the effect of different carbon sources viz. yam and potato on growth performance of milkfish (Chanos chanos) in biofloc‐based system. Milkfish fry (average body weight of 0.66 ± 0.01 g) was stocked in biofloc treatments, yam‐based biofloc (BFY) and potato‐based biofloc (BFP), and clear water (CW) as control in triplicates. Milkfish reared in biofloc‐based units obtained significantly better (p < 0.05) performance in terms of growth, digestive enzyme activity and survival when compared to clear water control. Among the biofloc‐based treatments, the highest average body weight (11.62 ± 0.24 g), specific growth rate (3.21 ± 0.01% day−1), percentage weight gain (1688.10 ± 19.05) and survival (90.83 ± 2.01%) were found in BFY group. Similarly, the essential amino acid and non‐essential amino acid contents of biofloc and experimental fish were higher in BFY as compared to BFP. Additionally, the highest level of EPA (eicosapentaenoic acid), DHA (docosahexaenoic acid) and total n‐6 and n‐3 PUFA were found higher in BFY. Bacterial composition analysis showed that BFY treatment groups had a more diverse bacterial community than those with BFP treatment groups. This study demonstrated that biofloc‐based culture system is suitable for rearing of C. chanos fry and the most preferable type of carbon source is found to be Yam.

Disease surveillance programmes provide information on diseases that mitigate aquaculture production. Infectious myonecrosis virus (IMNV) has emerged recently as one of the OIE (Office International des Epizooties, the World Organisation for Animal Health) listed viral diseases in penaeid shrimps, caused by dsRNA virus. The present study was conducted to investigate the prevalence of IMNV along the Indian coastal states. Samples of the Pacific whiteleg shrimp Penaeus vannamei and the green tiger shrimp Penaeus monodon were collected from 21 randomly selected active shrimp farms located along the coast using a risk-based two stage random sampling survey. Screening of the sampled shrimps based on nested RT-PCR diagnostic tool, did not detect IMNV in any of the samples examined indicating absence of IMN or IMNV incidence in shrimp aquaculture along Indian coastal states.