Channel catfish embryos and resulting larvae were exposed to several reduced dissolved oxygen concentrations and control concentrations near air saturation at 25 and 28 C (7.8 and 7.3 mg/liter, respectively). At 25 C survival was similar but slightly reduced at 60% and 70% saturation (5.0 and 5.8 mg/liter) and was statistically less (P=0.01) at 30% and 50% saturation (2.4 and 4.2 mg/liter). No embryos hatched at 20% (1.7 mg/liter) and 25 C. Survival to the end of the test at 28 C was slightly reduced at 50%, 60%, and 70% saturation (3.8, 4.6, and 5.4 mg/liter) and was statistically less (P = 0.01) at 30% saturation (2.3 mg/liter). At all reduced oxygen concentrations at 25 and 28 C embryo pigmentation was lighter, duration of hatch was extended, feeding was delayed, and growth was reduced.