| Contents Notes |
Chinook salmon, Oncorhynchus tshawytscha, were reared from fertilization of the eggs to several weeks after complete yolk absorption at dissolved oxygen concentration of 3.5, 5.0, and 7.3 mg/liter and air-saturation at temperatures of 10.5, 12.0, 13.5, and 15.0 C. Decrease of either temperature or dissolved oxygen concentration resulted in increase in the median (50%) hatching time of fry. Increase of temperature or decrease of dissolved oxygen concentration decreased mean dry weights of newly hatched fry and survival. Temperatures above 12.0 C resulted in substantially reduced survival at all dissolved oxygen levels tested. Large increases in mortality occurred during late embryonic and sac fry stages, the amount of mortality during each period being directly related to the prevailing test conditions. |
