Interpopulational variation in recovery time from chill coma along a geographic gradient:: A study in the common woodlouse, Porcellio laevis

Extreme temperatures restrict the performance of terrestrial arthropods and variations in low temperatures on it latitudinal scale influence physiological variables. Recovery time from chill coma is a measure of cold tolerance and it is a good index of climatic adaptation. We tested differences in recovery time of the common woodlouse (Porcellio laeris) exposed to different thermal conditions. Individuals were sampled from four dirferent Populations in Chile. spanning a latitudinal range of similar to 10. Significant differences were found in recovery time among experimental temperatures and among populations. but no interaction between these factors. The results of recovery time in P. laeris showed a positive increment with annual mean minimum temperature, indicating that there is geographical variation in recovery time. While body mass presented interopopulational variation. this variation was not associated with thermal variables or latitude. Overall, our results agree with previous Studies in the sense that recovery time from chill coma decreases towards high latitudes, and it is independent of taxa, continent and hemisphere. (c) 2005 Elsevier Ltd. All rights reserved.