International Journal of Fisheries and Aquatic Research

Authors
Rosidah, Isni Nurruhwati, Maria Dewi Yunita, Fittrie Meyllianawaty Pratiwy

Abstract
This research aims to determine the virulence of A. hydrophila bacteria with different densities which were infected to the goldfish (Carassius auratus). This research were used survey method with five treatments. The animal test were goldfish (Carassius auratus) infected by Aeromonas hydrophila bacteria with different density. The treatments divided into uninfected (Control / Treatment A), density of 10⁵ cfu / ml (treatment B), density of 10⁶ cfu / ml (treatment C), density of 10⁷ cfu / ml (treatment D) and density of 10⁸ cfu / ml (treatment E). The parameters observed were clinical symptoms which included fish damage body surface, feeding response, response to shock and survival rate. The data obtained were analyzed descriptively. The results of the study showed that the goldfish infected by Aeromonas hydrophila bacteria with different densities showed the different responses of surface damage such as inflammation, hyperemia/hemorrhage, ulcers, gill conditions, abscesses, response to feeding, and survival rate. Aeromonas hydrophila bacteria with a density of 10⁸ cfu / ml (E treatment) resulted the most severe body damage, low response to food, and very low survival rate (5%). The conclusion of this research is high density infection of Aeromonas hydrophila bacteria on the goldfish will give the high risk severe surface damage and high mortality rate. Aeromonas hydrophila with a density of 10⁸ cfu / ml (treatment E) infected in goldfish is categorized as a virulent.