The survival of freezing in the Siberian earthworm Eisenia nordenskioe
ldi was tested under dry conditions and in frozen soil. Worms cooled u
nder dry conditions to -4.5 degrees C for 24 hours had a mean temperat
ure of crystallisation of -3.5 degrees C. The survival rate of animals
exposed in frozen soil for 56 days was 50 to 82 % at temperatures bet
ween -4 and -10 degrees C. After warming to summer temperatures, anima
ls previously frozen produced viable egg capsules (cocoons). This is t
he first evidence for freeze-tolerance in an earthworm species.