Microbial Flora Associated with Limnodrilus hoffmeisteri Claparède, 1862, A Commercially Important Aquatic Oligochaeta (Tubifex Worm)

Limnodrilus hoffmeisteri (Tubifex worm) a commercially important aquatic Oligochaeta worm used as live feed for ornamental fishes were collected from Kolathur ornamental fish Market, Chennai, Tamilnadu India. during October 2024. DNA was extracted from ethanol-preserved specimen, followed by COI gene amplification, sequencing, and submitted to GenBank (accession no. PZ054017). Isolation of microbial flora from the worm collected from Kolathur ornamental fish Market, and the water sample of Kodungaiyur swamp were done by pure culture techniques. Identification of bacterial isolates from water sample from Kodungaiyur Swamp Chennai was done by partial gene sequencing of 16S rRNA followed by similarity search in NCBI - BLAST n algorithm. Sequences obtained show 100% similarity with Aeromonas hydrophila, Pantoea agglomerans, Acinetobacter sp and one fungal colony was isolated from the water sample from Kodungaiyur Swamp Chennai and was identified by 18S rRNA gene sequencing which showed 99% similarity with Aspergillus terreus. Sequences were deposited in the Genbank (accession numbers: PQ817788, PQ817809, PQ817848, PQ219291). The worm sample was homogenized and using pure culture techniques, three bacterial isolates were obtained, there was no apparent fungal growth. By comparing the biochemical characterization of 3 bacterial isolates it was revealed that these isolates were found to be phenotypically similar to Aeromonas hydrophila, Pantoea agglomerans, Acinetobacter sp. identified from the water sample of the Kodungaiyur swamp. From these findings it is inferred that “Tubifex worms” collected form wild habitats contains potential pathogens and need to be disinfected before feeding the aquaculture organisms in order to achieve efficient disease management in ornamental fishes.