Rapid cold hardening: A gut feeling

This study examined the rate of cold hardening of a field population of Ant arctic springtails and the effect of eating food with particular levels of ice nucleating activity on the animal's whole body freezing point. The SCPs of samples of c. 20, freshly collected, Cryptopygus antarcticus were measu red hourly over a 32 hour collection period using differential scanning cal orimetry and related to habitat temperature. The mean SCP of the springtail s increased from -24 to -10 degreesC during which time the habitat temperat ure warmed slowly from -2.5 to +2.5 degreesC. In laboratory experiments, previously starved, cold tolerant springtails we re fed on selected species of algae with measured SCP's but there was no cl ear correlation between the SCP of food and that of the animals after feedi ng. Microscopic examination of faecal pellets and guts from springtails sho wed that algal cells were completely destroyed during digestion.