Effects of gamma radiation on the survival and growth of brine shrimp, Artemia salina

To determine the effects of gamma radiation on the survival and growth of brine shrimp, nauplii and adults were exposed to different doses of radiation and maintained at different salinities and temperatures. The LD50 determination demonstrated that nauplii were thirty to forty times more sensitive than the adults and had a 25-day LD50 of 450 rads. Radiation and salinity reduced survival of adult female brine shrimp more than the males. The interaction of salinity, 5 and 50 ppt, temperature, 10, 20 and 300C, and radiation, 25 to 100 kilorads, decreased the survival of both male and female brine shrimp, with the males having the greater sensitivity. Brine shrimp nauplii irradiated with doses of 500 and 2,500 rads had accelerated growth and matured earlier than the controls. A test of the effect of crowding on growth showed that volume per individual was important, and a dose of 500 rads accelerated brine shrimp growth in all concentrations, with the greatest increase at 8 ml/nauplius