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ARS Home » Southeast Area » Stuttgart, Arkansas » Harry K. Dupree Stuttgart National Aquaculture Research Cntr » Research » Publications at this Location » Publication #233142

Title: Acute toxicity of peracetic acid (PAA) formulations to Ichthyophthirius multifiliis theronts

item Straus, David - Dave

Submitted to: Parasitology Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/20/2009
Publication Date: 3/23/2009
Citation: Straus, D.L., Meinelt, T. 2009. Acute toxicity of peracetic acid (PAA) formulations to Ichthyophthirius multifiliis theronts. Parasitology Research. 104:1237-1241.

Interpretive Summary: Ich is a fish parasite found throughout the world which appears as small white spots the size of a pin head. They can be devastating to aquaculture and can be passed to nearby facilities through poor management practices. An antimicrobial disinfectant called peracetic acid is being tested for use to treat Ich. This study looked at the acute toxicity of this compound to the free-swimming life stage of Ich that was obtained from golden shiner minnows (from Arkansas) and swordtail tropical fish (from Florida). We found that there is a difference between the golden shiner Ich and the swordtail Ich, with the golden shiner Ich being able to tolerate a higher concentration of the compound.

Technical Abstract: Peracetic acid (PAA) is an antimicrobial disinfectant used in agriculture, food processing and medical facilities. It has recently been suggested as a means to control infestations of Ichthyophthirius multifiliis. The purpose of this study was to determine the acute toxicity of two products containing 4.5% and 40% PAA to I. multifiliis theronts from two geographically separate isolates. Theronts were exposed to concentrations of PAA in 96-well plates containing groundwater at 23°C. Acute toxicity was observed over a 4 h period. No significant difference in the median lethal concentration (LC50) estimates was evident between the two isolates at 4 hrs with the 4.5% PAA product (0.146 versus 0.108 mg/l PAA), while there was a statistical difference between the 4 hr LC50 estimates with the 40% PAA product (0.274 versus 0.158 mg/l PAA). These results suggest that PAA is toxic to I. multifiliis theronts at low concentrations and that one of the isolates was more resistant to this compound.