Observations on Hydrogen Peroxide Control ofSaprolegniaspp. during Rainbow Trout Egg Incubation

Daily treatments of 250, 500, and 1,000 mg hydrogen peroxide/L for 15 min were evaluated for fungal control on incubating eggs from two strains of rainbow trout Oncorhynchus mykiss. Observed infection rates and egg clumping were extensive enough in incubator trays receiving treatments of 250 or 500 mg hydrogen peroxide/L to make egg and fry handling difficult. The 1,000 mg/L treatment provided fungal control similar to daily formalin treatments of 1,667 mg/L for 15 min. Despite the differences in infection rates and clumping, egg survival was not affected by any of the treatments used.