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ARS Home » Southeast Area » Stuttgart, Arkansas » Harry K. Dupree Stuttgart National Aquaculture Research Cntr » Research » Publications at this Location » Publication #307252
Title: Using copper sulfate on hybrid striped bass eggs to control fungus and increase survival

Author
item Straus, David - Dave
item Beck, Benjamin
item Farmer, Bradley
item Ledbetter, Cynthia - Cindy
item WILLIAMS, RICK - Keo Fish Farm
item CLARK, MIKE - Central Arkansas Fisheries
item FREEZE, MIKE - Keo Fish Farm

Submitted to: University of Arkansas-Pine Bluff Aquaculture Field Day
Publication Type: Abstract Only
Publication Acceptance Date: 9/15/2014
Publication Date: 10/2/2014
Citation: Straus, D.L., Beck, B.H., Farmer, B.D., Ledbetter, C.K., Williams, R.S., Clark, M.L., Freeze, M.T. 2014. Using copper sulfate on hybrid striped bass eggs to control fungus and increase survival. University of Arkansas-Pine Bluff Aquaculture Field Day. p. 29.

Interpretive Summary:

Technical Abstract: A major obstacle in fish hatcheries is reduced hatch rates due to fungal growth on eggs. Copper sulfate (CuSO4) is commonly used for fungus control in catfish hatcheries that use troughs, but effectiveness on other species of fish eggs in different hatching systems has only recently been investigated. Fish were spawned at Keo Fish Farm and hybrid striped bass eggs were transferred to 1 1/2 gallon McDonald jars for processing with tannic acid (removes stickiness) and iodine (disinfectant). Our experimental egg hatching jars were 1/3 this size, so egg density was adjusted accordingly. Because eggs start hatching after 2 days, CuSO4 treatment began the afternoon of spawning with a 10 minute aerated, static bath and was repeated the morning and afternoon of Day 2. There were three CuSO4 concentrations tested (10, 20, and 40 ppm) and a control with untreated eggs. Hatched larvae were counted with an XperCount™ bucket which measures biomass. Fungus was severe in the controls (28% survival). Very little fungus was present in treatments receiving 10 ppm CuSO4 (32% survival) or higher. The best survival was at 40 ppm CuSO4 (50% survival); however, the 20 ppm CuSO4 treatment (46% survival) gave similar results and allows for a greater margin of safety. During this study we noticed that the eggs stayed blue after being exposed to CuSO4 which indicates that it gives a lasting effect. The hybrid striped bass industry is currently using this treatment.