Submitted to: Book of Abstracts World Aquaculture Society
Publication Type: Abstract Only
Publication Acceptance Date: 7/17/2003
Publication Date: 3/1/2004
Citation: Straus, D.L. 2004. Efficacy of copper sulfate in preventing mortality due to ichthyophthiriasis in channel catfish - a simulated field study [abstract]. Book of Abstracts World Aquaculture Society. p. 563.
Technical Abstract: Epizootics of Ichthyophthiriasis can be controlled with copper sulfate (CuSO4), but its effectiveness has not been confirmed in field studies. The purpose of this study was to determine the concentration of CuSO4 needed to control mortality associated with an Ichthyophthirius multifiliis infestation on channel catfish Ictalurus punctatus in a simulated pond environment. Ichthyophthiriasis infestations are common in the spring and fall of the year when temperatures are cool; experience in our lab has indicated 18°C is the optimum temperature. For this study, a temperature controlled room maintained the water temperature at 18 ± 1 °C. Juvenile channel catfish were exposed to I. multifiliis-infested fish until they developed immature trophonts. Twenty fish were then placed in each of 15 static fiberglass tanks containing 600 L of pond water and treated with CuSO4 every other day for 4 treatments; the study was maintained for 10 days post-treatment for a total of 17 days. Total alkalinity was 220 mg/L (as CaCO3) and treatment rates were 0.0, 1.1, 2.2, 3.3, and 4.4 mg/L CuSO4; survival after 17 days was 0, 85, 18, 2, and 3 %, respectively. The typical treatment rate for aquaculture ponds is 1 mg/L CuSO4 for every 100 mg/L total alkalinity, or 2.2 mg/L CuSO4 in the present study. The results indicate that CuSO4 is effective for controlling mortality associated with I. multifiliis epizootics at half the recommended treatment rate in our water. However, effective treatment in channel catfish ponds will also be influenced by other water chemistry and pond sediments.