Studies on factors affecting survival of nile fish in the Sudan. III. The effect of oxygen

Tilapia nilotica L. were exposed to different levels of ambient oxygen concentrations for 24 h periods. Nitrogen was bubbled through the water to reduced the oxygen concentration to the respective test level. When testing concentrations of oxygen between 2.5 and 0.4 ppm over 24 h periods of exposure, the median tolerance limits (TLM) over 24 h were attained at 1.41 ppm of oxygen.