Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/22/2011
Publication Date: 6/26/2012
Citation: Farmer, B.D., Beck, B.H., Straus, D.L. 2012. Effectiveness of copper sulfate and potassium permanganate on channel catfish infected with Flavobacterium columnare. North American Journal of Aquaculture. 74(3):320-329.
Interpretive Summary: Columnaris disease is a bacterial disease of channel catfish that causes large economic losses to catfish farmers. In this study, the use of two chemicals, copper sulfate (CuSO4) and potassium permanganate (KMnO4) were evaluated for treating Columnaris disease in channel catfish. These chemicals were applied to the water of infected fish once per day for three consecutive days. The treatment rate for CuSO4 was 2.1 mg/L, and the rate for KMnO4 was 3.0 mg/L. The effects of these chemicals on fish survival and on the number of disease causing bacteria both in the water and on the fish were evaluated. Copper sulfate improved fish survival and lowered the number of bacteria in the water and on fish. Potassium permanganate did not improve survival, but did lower the number of bacteria in the water. These results will help catfish farmers reduce losses to columnaris disease and produce more and healthier fish.
Technical Abstract: Copper sulfate (CuSO4) and potassium permanganate (KMnO4) were evaluated for their effectiveness to curtail mortality and decrease bacterial load in fish tissues and water in channel catfish Ictalurus punctatus naturally infected with Flavobacterium columnare, the causative agent of columnaris. Fish (16.6 g and 13.7 cm) were randomly selected from a single culture tank undergoing a natural epizootic of columnaris and were stocked at a density of 30 per tank in each of 12 tanks. The study consisted of four replications of three treatments: a control group without exposure to CuSO4 or KMnO4, a CuSO4-treated group, and a KMnO4-treated group. Treatment rates were 2.1 mg/L CuSO4 and 3.0 mg/L KMnO4 and were applied on three consecutive days at 24 h intervals. Caudal fin, gill, and liver samples were taken from one fish of each replication 24 h after the last treatment for analysis by quantitative real time polymerase chain reaction (qPCR). Water samples were taken for CuSO4 and KMnO4 dose-confirmation and for qPCR analysis. A significant improvement in survival was noted among channel catfish treated with CuSO4 (72.7%) as compared to the control fish (38.5%). Survival was not statistically different from the control for channel catfish treated with KMnO4 (52.2%). Quantitative PCR data showed a significant reduction of bacteria in the water following the first and second treatments of both therapeutants, yet no difference was detected in fish tissues. Histological analysis of gill samples 24 h after the last treatment indicated that CuSO4-treated fish exhibited significantly less gill damage than untreated controls, there was no difference in KMnO4 treated fish.