Effects to Skeletal Structure

Long periods of dormancy in mammals typically results in weaker bones and bone remodeling. Confinement can cause "demineralisation, decrease in size and corresponding loss of bone strength" (Hudson et al., 2004). In Cyclorana, however, there appears to be no adverse effects to bone structure after aestivation. After aestivation, individuals can still hop as far as individuals that did not aestivate. Aestivation also appears to have no affect on the durability of bones. Bones of post-aestivation frogs are just as resistant to bending as control frogs (2004). In addition, there is no evidence that bone deterioration occurs. Osteocytes, or bone cells, are equally distributed in bones of post-aestivation Cyclorana. This continues to support the behavior of Cyclorana that they need to be able to hunt, as well as avoid predators, as soon as they emerge from aestivation.

Cyclorana novaehallandiae (from James Cook University; permission given by Betsy Jackes)

It is argued that Cyclorana and other burrowing amphibians are able to retain skeletal structure because they are relatively inactive to begin with (2004). Being ectotherms (cold-blooded), Cyclorana depend on the environment for heat, not metabolic functions. This means they can sit and wait for food, sometimes for weeks at a time. Since Cyclorana already live this inactive lifestyle, aestivation is not as strong a stimulus as hibernation is for mammals (2004).