[The change of Daphnia magna viability after low doses of gamma-irradiation].

The gamma-irradiation in the dose 0.001 Gy didn't influence to the Daphnia magna Straus survival in the parents generation, cultivating during 30 days. At the some time the irradiation in dose 0.01 Gy had considerable increased the level of them died. This reaction was saving during the increase of the doses to 0.1, 1 and 20 Gy. So in this doses the interval had been gradual and didn't depend from dose, decreasing the number of this population, which significant top the control level. In more high doses--100, 250 and 600 Gy was observed the transfer to the stronger lethal effects, which increased with the doses' grow. Daphnia are the plankton animals, which live in a huge numbers in fresh reservoirs. So the decrease of their population after gamma-irradiation in low and high doses has been interested as a radioecology problem.