Animals may use muscles as an internal water source

Turns out, animals may be able to use their own muscles to get water when it's not available.

Water is vital for life. But as our climate changes, the availability of water also changes, leaving animals with limited or unreliable supplies of this critical resource.

The researchers at the Arizona State University looked into this concept by studying the effects of water deprivation on the reproductive efforts of female Children's pythons.

Pythons, a medium-sized snake that reproduces during the dry-season in Australia, where natural water sources are extremely limited.

They found that muscles play an important role in providing water to the body when none is available.

During the study, the researchers paired pregnant Children's pythons with similarly sized non-reproductive females. During a three-week period when the snakes were pregnant, only half of the pairs had access to water. Reproductive females, both in the lab and the wild, don't eat during pregnancy and rely on internal reserves such as fat and muscle for their energy needs.

They then measured the by-products of burning fat and muscle such as ketones and uric acid, as well as muscle size and impact on the snakes' eggs and clutch sizes. The animals without water burned more muscle than fat to meet their water requirements. In addition, the animals without water laid a similar number of eggs per clutch, but their eggs weighed less and the shells were thinner.

"Our enhanced knowledge regarding the relationship between hydration and reproductive investment will also enable us to better understand global responses to water limitations and change the way scientists approach reproductive investment in ecological contexts, which, in the past, frequently ignore water and focus solely on energetic resources," explained George Brusch, lead researcher of the study.

Most animals need steady access to water in order to survive, especially during reproduction, and the authors suggest that using muscle as a water store may be a widespread phenomenon.

The findings appeared in the Journal of Proceedings of the Royal Society B: Biological Sciences.