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Submitted to: Book of Abstracts Aquaculture America
Publication Type: Abstract Only Publication Acceptance Date: 12/13/2005 Publication Date: 2/13/2006 Citation: Straus, D.L. 2006. Acute toxicity of copper sulfate to channel catfish fry at various ages: Well water vs. diluted well water [abstract]. Aquaculture America 2006 Book of Abstracts. p. 304. Interpretive Summary: Technical Abstract: Interest in the use of copper sulfate as a control for fungus (Saprolegnia sp) on channel catfish eggs has grown over the last few years. There are plans underway to investigate the efficacy of this compound along with other studies that are necessary to gain FDA-approval for its use as a fungicide in hatcheries, but little is known of the acute toxicity of CuSO4 to fry. The purpose of this study was to determine the 24 hour LC50 (median lethal concentration) of CuSO4 to channel catfish sac-fry and swim-up fry. Several strains of channel catfish fry were exposed to CuSO4 in a series of static toxicity tests in waters composed of filtered (75 µm) well water or filtered well water diluted with deionized water. The LC50 estimates were determined >24 hours after hatching (sac-fry) and at 7 – 8 days (swim-up fry). The 24 hr LC50 values for sac-fry ranged from 25 - 52 and 2 - 11 mg/L CuSO4 in waters having total alkalinities of 215 and 113 mg/L (as CaCO3), respectively. The 24 hr LC50 values for swim-up fry ranged from 5 - 30 and 2 - 12 mg/L CuSO4 in waters having total alkalinities of 215 and 113 mg/L (as CaCO3), respectively. Results indicate that channel catfish sac-fry are 2.4 times more sensitive to CuSO4 and swim-up fry are 4.1 times more sensitive to CuSO4 in waters of lower alkalinity. |
