Meeting Abstract
Water is an essential resource, and animals obtain water as free water, dietary water, and metabolic water. However, when sources of new water are limited, animals can reallocate water within their body. Recent research suggests that organisms under dehydrating conditions may increase the catabolism of muscle as a means of maintaining water balance, since muscle contains a greater proportion of water than does fat, yielding more water for reallocation. We investigated the interactive effects of reproductive investment and water deprivation on fat and muscle catabolism in female Children’s pythons (Antaresia childreni), a species that reproduces during a highly food- and water-limited dry season. Both reproductive and non-reproductive snake were maintained at a constant temperature and without food. Half the females of each group were deprived of water for three weeks at the time when reproductive females were gravid. We used several morphometric and biochemical assessments to measure changes in lipid and protein catabolism when reproductive females were in late vitellogenesis and late gravidity. Not surprisingly, we found that both protein and fat catabolism was significantly greater during vitellogenesis compared to the gravid and non-reproductive states. Of greater interest, reproductive females that were water-restricted during gravidity catabolized significantly higher amounts of muscle than did non-reproductive females or gravid females with access to water. Our results provide evidence that, when water availability is limited, muscle can serve as a depot for reallocation to other water-demanding processes.
