Copper sulfate is an effective and less expensive treatment for fish infected by Ichthyophthirius multifiliis, also known as “Ich,” as well as fish eggs with Saprolegnia, according to David Straus, an aquatic toxicologist with the U.S. Department of Agriculture’s Agricultural Research Service (ARS).
The USDA reported the finding last week and the research appears in the October issue of Agricultural Research magazine.
Ich, a protozoan parasite that appears as white spots on infected fish, is considered the most prevalent parasite worldwide in ornamental fish, baitfish and food fish, according to Straus, who works at the ARS Harry K. Dupree Stuttgart National Aquaculture Research Center in Stuttgart, Ark.
Saprolegnia is a fresh water fungus that kills eggs and invades wounds and lesions on juvenile and adult fish.
In addition to being effective and inexpensive for such treatments, copper sulfate is also safer for the handler, according to Straus. For example, formalin and hydrogen peroxide, both current approved treatments for fungus on eggs, have human safety concerns as well as required storage precautions, Straus noted.
The U.S. Food and Drug Administration has not yet approved copper sulfate for therapeutic use in aquaculture. However, regulatory action has been deferred pending the outcome of Straus’ ongoing research, according to the USDA.