Isolation and identification of bacterial gill disease in goldfish, Carassius auratus in Madurai

Abstract

Aquarium fish sometimes suffer from a disease complex called bacterial gill disease. Although it most often affects young fishes, it can affect any type of aquarium fish. The bacterial gill disease (BGD) were diagnosed in goldfish Carassius auratus purchased from Madurai. Histologically, the fish from all outbreaks had large numbers of filamentous bacteria associated with the gill tissue. The bacterial species such as Flavobacteria, Aeromonas and Pseudomonas spp. were isolated from the experimental fishes. The results of this present work, concludes that the ornamental fishes from Madurai district indicate that the pathogenic bacteria species were abounded in the aquarium. Epidemics of bacterial diseases are common in dense populations of cultured food or aquarium fish. Predisposition to such outbreaks frequently is associated with poor water quality, organic loading of the aquatic environment, handling and transport of fish, marked temperature changes, hypoxia, or other stressful conditions. Most bacterial pathogens of fish are aerobic, gram-negative rods. Diagnosis is by isolation of the organism in pure culture from infected tissues and identification of the bacterial agent.