Hydrogen Peroxide Treatment during Egg Incubation Improves Channel Catfish Hatching Success

—Three trials were conducted to evaluate the effect of hydrogen peroxide (H2O2) treatment on the hatching success of channel catfish Ictalurus punctatus when administered during egg incubation as a 15-min bath or as a flow-through treatment. In the first trial, initial treatment with 100 mg povidone iodine/L followed by daily 15-min baths of 250 mg H2O2/L yielded a 26% increase (P , 0.05) in hatching success above controls. In the second trial, daily 15-min baths with H2O2 (250 mg/L) yielded a 30% increase (P , 0.05) in hatching success compared with povidone-iodine-treated controls and significantly improved hatching success compared with formalin-treated (1,600 mg/L) eggs. In the third trial, hydrogen peroxide was administered in flow-through hatching troughs. Egg masses treated with 70 mg H2O2/L had significantly improved (P , 0.05) hatching success compared with untreated controls (68.3% and 24.2%, respectively). The results of this research show that significant improvements in channel catfish hatching success can be obtained through the use of hydrogen peroxide as a cost-effective alternative to formalin. Commercial channel catfish farmers typically report average hatch rates of 60–80%; however, fungal and bacterial egg infections can pose significant problems for hatcheries (Brunson 1992), resulting in highly variable hatching success. Potential infections are often controlled with chemical therapeutics such as povidone iodine or formalin (Brunson 1992; Walser and Phelps 1993). Povidone iodine is designated by the U.S. Food and Drug Administration (FDA) as a low regulatory priority (LRP) aquaculture drug when used as an egg surface disinfectant, and formalin is approved by the FDA for the control of fungi of the family Saprolegniaceae on the eggs of all finfish. Although formalin is an effective therapeutic, concerns of safety exist among users due to its suspected carcinogenicity and odoriferous nature. Hydrogen peroxide (H2O2) has been investigated as * Corresponding author: [email protected] Received October 2, 2002; accepted March 21, 2003 an alternative treatment to control egg diseases in a number of fish species (Rach et al. 1998; Ardt et al. 2001), and is currently designated by the FDA as an LRP aquaculture drug when administered at 250–500 mg/L. For the research presented here, three trials were conducted to evaluate the effect of hydrogen peroxide treatment on channel catfish hatching success when administered as a 15-min bath or as a flow-through treatment representative of a commercial hatchery situation.