METAGENOMIC ANALYSIS OF GUT MICROBIAL DIVERSITY IN FISH FROM GANGA RIVER AND POND ECOSYSTEMS Department of Zoology, Dayanand Girls’ Post Graduate College, Kanpur - 208 001, India., Hemprabha Hemprabha, Sunita Arya Journal of Experimental Zoology India, 2026 Metagenomics, the study of genetic material recovered directly from environmental samples, enables comprehensive analysis of entire microbial communities via high-throughput DNA sequencing, providing a culture-independent approach to explore microbial composition and functional potential in diverse ecosystems. In the present study, gut microbiomes of Labeo rohita from contrasting habitats pond water and the Ganga River were compared using Illumina MiSeq sequencing of the V3–V4 regions of the 16S rRNA gene from gut contents of clinically healthy adult fish, with standard bioinformatics pipelines applied for characterization. Alpha diversity was higher in pond fish (Shannon index: 2.02 ± 0.02) than river fish (1.86 ± 0.01), while beta diversity revealed clear habitat separation (average Bray–Curtis dissimilarity: 30%); taxonomically, Firmicutes dominated pond samples, whereas Proteobacteria including stress- or opportunism-associated genera like Aeromonas and Pseudomonas prevailed in river fish, with fermentative and potentially beneficial taxa such as Lactobacillus, Clostridium, and Bifidobacterium more abundant in ponds. LEfSe analysis linked Nitrospirae, Deinococcus-Thermus and Balneolaeota to pond habitats and Ignavibacteriae and Elusimicrobia to river samples, while PICRUSt-based functional predictions indicated elevated carbohydrate, amino acid, and vitamin metabolism in pond fish versus enrichment in detoxification and stress-response pathways in river fish. These results highlight substantial environmental influence on Labeo rohita gut microbial communities, suggesting that managed pond systems may promote assemblages supportive of host health, growth, and resilience, whereas river fish could be more prone to microbial imbalance, offering insights for microbial modulation strategies to potentially reduce disease risks in aquaculture.
Assessment of water pollution of river ganga by tannery effluent using fish as a bio-indicator in Kanpur, India Biochemical and Cellular Archives, 2016
