FREEZE-TOLERANCE IN THE SUB-ARCTIC EARTHWORM EISENIA-NORDENSKIOELDI (EISEN)

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.