Treatment Of Flavobacterium columnare Infection In Channel Catfish (Ictarulus punctatus)     Praparsiri Srisopaporn1, Thomas E. Schwedler1, Charles D. Rice2, Ian R. Dorociak1   1Department of Aquaculture, Fisheries, and Wildlife Biology, Clemson University, Clemson; 2Department of Environmental Toxicology, Clemson University, Clemson, SC     Columnaris Disease Flavobacterium columnare often occurs after handling, causing significant losses. This study investigates the effect of two therapeutants reported to control columnaris disease. Subsequent to severe losses of a group of channel catfish (Ictarulus punctatus)to columnaris post handling, a second group was handled similarly and moved into 40 aquaria. The fish were assigned randomly to 5 groups of eight replicates.The groups were 1) a single potassium permanganate treatment,2) a potassium permanganate every other day treatment,3) an Oxy-tetracycline prophylactic treatment,4) an Oxy-tetracycline onset treatment, and 5) a control group. The F.columnare infection was severe with onset of mortality at 2 days and 92% of the control fish dead by day 4 post handling. The two potassium permanganate treatment groups appeared to have no therapeutic effect with mortality at day 4 being 89 to 93 %. The prophylactic Oxy-tetracycline group had no mortalities by day 4 nor had any died by day 14 of the study. The onset Oxy-tetracycline group began medicated feed on day 2 when 17.5 % of the fish died. The mortality peaked on day 4 at 26.5 % and remained at that level until day 14. The two Oxy-tetracycline treatment regiments were very effective in preventing and curing naturally induced F. columnaris infections.