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Safety of Copper Sulfate to Channel Catfish Eggs
Author(s) -
Straus David L.,
Mitchell Andrew J.,
Carter Ray R.,
McEntire Matthew E.,
Steeby James A.
Publication year - 2012
Publication title -
north american journal of aquaculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 41
eISSN - 1548-8454
pISSN - 1522-2055
DOI - 10.1080/15222055.2011.649889
Subject(s) - catfish , ictalurus , hatching , biology , saprolegnia , copper sulfate , zoology , fishery , copper , toxicology , veterinary medicine , chemistry , fish <actinopterygii> , medicine , organic chemistry
Copper sulfate (CuSO 4 ) is used in the catfish industry to control saprolegniasis (caused by the watermolds Achlya spp. or Saprolegnia spp.) on eggs. This study was designed to establish the margin of safety of CuSO 4 at 10, 30, and 50 mg/L when applied for three times the normal treatment duration to hatching troughs containing channel catfish Ictalurus punctatus eggs in 26°C, flow‐through well water. The safety of CuSO 4 was indicated by the percentage of fry that hatched from the eggs. Eggs were treated daily until the embryos reached the eyed stage. The least‐squares means ± SE of hatch rates were 40.8 ± 9.1, 80.9 ± 6.4, 64.2 ± 8.6, and 80.3 ± 6.6% for the 0‐, 10‐, 30‐, and 50‐mg/L CuSO 4 treatments, respectively. The hatch rate for the 0‐mg/L CuSO 4 treatment was significantly different from that of all other CuSO 4 treatments. Treating channel catfish eggs with five times the recommended dose of 10‐mg/L CuSO 4 for three times the recommended duration did not adversely affect the hatch rates in this study. There appears to be an adequate margin of safety above the therapeutic dose of 10 mg/L for channel catfish eggs; therefore, CuSO 4 should be considered a safe treatment to alleviate egg losses caused by saprolegniasis.