Identification, characterization of fungus which infects domestic fishes and its prevention using plant extracts

Abstract

Fish fungus is one of the main concerns of people who culture fishes in hatcheries and aquariums as they adversely affect fishes leading to its death. Chemical formulations are used to treat fungus growing on fishes but not all fishes can be cured with the chemical formulations and the effects of these chemicals maybe shown when human consumes those fishes. Hence, it is always better to go for medicine from natural sources to treat these kinds of diseases. In this study, we have isolated fish fungus by culturing infected part of fishes Carassius auratus and Cyprinus carpio on Potato dextrose agar. The fungus was allowed to grow for 5–7 days at 28-30 ˚C, white spongy and grey colonies were observed. Genomic DNA was isolated from fungus and ITS gene was PCR amplified. They were further characterized using Sanger sequencing method to characterize its taxonomic nature of fungus and its growth properties. Further few common plants having antimicrobial properties were used to inhibit the growth of these funguses using agar well diffusion method. The results showed that the isolated funguses are Aspergillus fumigatus and Saprolegnia parasitica when sequences were subjected to NCBI BLAST. The results of antimicrobial studies highlighted the effect of ethanolic leaf extracts of Cardiospermum helicacabum, Kirganelia reticulata, Urena lobata, Vitex negundo, Scoparia dulcis and Pongamia pinnata plants against growth of above mentioned pathogenic fungus.