Influence of Water Quality on the Incidence of Diseases in Ornamental Fishes in Tamilnadu (India)

Influence of water quality on the incidence of bacterial and parasitic diseases in ornamental fish farms and ornamental fish outlets was studied in selected districts of Tamil Nadu (India). The diseases incidence in fish varied with season with higher incidence during summer. Water quality parameters like temperature, pH, oxygen, ammonia and total organic carbon showed direct influence on disease incidence. Total organic carbon and ammonia showed significant (p<0.01) correlation with bacterial pathogens. High stocking, poor water quality, unbalanced feed, transportation were the factors responsible for stress in fish. Multiple linear regression analysis proved that the adjusted R² value for estimated function was 0.762 which implied that 76.2% variation in the incidence of parasitic and bacterial infection in ornamental farms was related to water quality parameters like ammonia and total organic carbon. The bacterial diseases observed were dropsy with myxobacterial infection, bacterial ulcer and hemorrhagic septicemia. The abundance of parasites was more dependent on ammonia and total organic carbon contents which influenced the susceptibility of fish to the diseases.