Submitted to: Journal of Aquatic Animal Health
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 4, 2001
Publication Date: June 1, 2002
Citation: STRAUS, D.L., GRIFFIN, B.R. EFFICACY OF POTASSIUM PERMANGANATE IN TREATING ICHTHYOPHTHIRIASIS IN CHANNEL CATFISH.. JOURNAL OF AQUATIC ANIMAL HEALTH. 2002. v.14. p.145-148. Interpretive Summary: Ich or whitespot disease is caused by an external protozoan parasite (Ichthyophthirius multifiliis) that invades the skin and gills of freshwater fish. The life cycle of Ich usually takes 5 - 7 days depending on water temperature and involves a microscopic infective stage (theront) that burrows into the skin or gill of fish to feed on mucus and tissue. Killing the infective free- swimming theront or the detached trophont with various anti-protozoal drugs can stop the reproductive cycle and prevent spread of the disease to other fish. Juvenile channel catfish were exposed to an Ich infested fish until they developed immature trophonts. They were then moved to individual glass containers with 1/2 gal of well water and were treated with doses of KMnO4 ranging from 0 to 1.5 ppm daily; water was exchanged daily before treatment. The study was ended when the control fish (0 ppm KMnO4) died on Day 10. The lowest dose of KMnO4 that completely eliminated the Ich was 1.25 ppm.
Technical Abstract: Epizootics of ichthyophthiriasis can be controlled with potassium permanganate (KMnO4), but reports of its effectiveness have not been confirmed by controlled efficacy studies. The purpose of this study was to determine the concentration of KMnO4 needed to halt an active Ichthyophthirius multifiliis infestation in channel catfish Ictalurus punctatus. Juvenile channel catfish were exposed to I. multifiliis-infested fish until they developed immature trophonts. They were then moved to individual static containers with 2 L of filtered well water and were treated with KMnO4 daily for 10 days; water was exchanged daily prior to treatment. The lowest effective dose (dose required to eliminate theronts) of KMnO4 was 1.25 mg/L. These results indicate that KMnO4 is effective for controlling I. multifiliis epizootics at low concentrations in clean water. However, effective treatment of pond water will be strongly influenced by detoxication of KMnO4 based on the concentration of easily oxidizable substances in the water.