Efficacy of hydrogen
peroxide to control saprolegniasis on channel catfish (Ictalurus
punctatus) eggs
J.J. Rach, J.J. Valentine, T.M. Schreier, M.P.
Gaikowski, T.G. Crawford-2004
Aquaculture, 238: 135-142
Abstract:
The efficacy of hydrogen peroxide to control
mortality associated with saprolegniasis in channel catfish (Ictalurus
punctatus) eggs was evaluated at the Lost Valley State Fish Hatchery
(Warsaw, MO). Two efficacy trials were conducted. In Trial 1, channel
catfish eggs in their natural gelatinous matrix were treated with hydrogen
peroxide at 0, 500, and 750 mg l−1. Channel catfish eggs in
Trial 2 had the gelatinous matrix removed before treatment with hydrogen
peroxide at 0 and 500 mg l−1. Each treatment regimen was
tested in triplicate and each egg jar contained ~17,400 eggs. Hydrogen
peroxide was administered as a 15-min flow-through treatment applied once
daily for a total of six applications. Control jars were similarly treated
with culture water. Samples of exposure water were collected during each
treatment and analyzed to verify actual treatment concentrations. Hydrogen
peroxide treatment efficacy was assessed by comparing the percent egg hatch
in the treatment group to the untreated control group in each trial. Mean
percent hatch in Trial 1 was 44% (control), 54% (500 mg l−1),
and 69% (750 mg l−1). Hydrogen peroxide treatment at either
500 or 750 mg l−1 significantly (P<0.01)
increased the percent hatch compared to the untreated control group. In
Trial 2, hydrogen peroxide treatment at 500 mg l−1
significantly (P<0.01) increased the percent egg hatch (67%)
relative to the untreated controls (57%). Hydrogen peroxide treatment
reduced egg mortality and increased the percent hatch of channel catfish
eggs regardless of whether eggs were incubated in the gelatinous matrix or
without the matrix in comparison to the untreated control.
(U.S. Geological Survey, Upper Midwest Environmental
Sciences Center, 2630 Fanta Reed Road, La Crosse, WI 54603, USA, e-mail: Jeffrey_Rach@usgs.gov)