Comparison of Percent Hatch and Fungal Infestation in Channel Catfish Eggs after Copper Sulfate, Diquat Bromide, Formalin, and Hydrogen Peroxide Treatment

Abstract

Reduced survival of fish eggs is often a result of infestation with fungi Saprolegnia spp. However, timely chemical treatments often limit these infestations and increase survival. The effect of copper sulfate pentahydrate (CSP; 10 mg of CSP/L of water), diquat bromide (25 mg of diquat cation/L), formalin (433 mg/L), and hydrogen peroxide (H₂O₂; 250 mg/L) on percent hatch and fungal infestation in eggs of channel catfish Ictalurus punctatus was compared in two identical trials (five replicates for each chemical treatment per trial). The percent hatch in all chemical treatments was significantly better than percent hatch of the controls. The amount of fungal coverage on egg masses treated with CSP, formalin, and H₂O₂ was significantly less than that observed on the controls. Although not statistically different from the other treatments, H₂O₂ at 250 mg/L exhibited the highest average percent hatch (64%; control hatch = 34%), the lowest fungal coverage (1.5 cm; control coverage = 7.2 cm), and the lowest occurrence of fungi (50%; control occurrence = 100%) among the treatments.