Microbiome Analysis of Gut Bacterial Communities of Healthy and Diseased Malaysian Mahseer (Tor tambroides)

AimsThe gut microbiota is referred to an extra organ and is ciritical in assisting the host in terms of nutrition and immunity. Environmental stressors could alter gut microbial community and cause gut inflammation. This study aimed to investigate and compare the gut microbiota community between healthy and diseased Tor tambroides. Methodology and resultsIn this study, such gut microbial alterations were explored using NGS-based 16S rDNA sequencing on the Malaysian mahseer (T. tambroides). Three adult healthy and three diseased adult Malaysian mahseers (showing signs of exophthalmia, coelomic distension and petechial haemorrhage) were obtained from LTT Aquaculture Sdn Bhd. Our results revealed significant differences in microbial diversity, composition and function between both populations of T. tambroides. Alpha diversity analysis depicts lower diversity of gut microbiota composition in diseased T. tambroides as compared to the healthy group. In particular, Enterobacteriaceae, Aeromonas, Bacteroides, Vibrio and Pseudomonas were found within gut microbiota of the diseased fishes. In addition, cellulose-degrading bacteria and protease-producing bacteria were identified from the gut of T. tambroides. Conclusion significance and impact of studyThus, our findings emphasised on the association between the alteration in gut microbiota composition and infectious abdominal dropsy (IAD) in T. tambroides. This finding is important to provide basic information for further diagnosis, prevention and treatment of intestinal diseases in fish.