African mouse lets predators shred its skin

Acomys kempi, one of two species of African spiny mouse found to shed and regrow chunks of skin / Courtesy: Nature

By John Upton

Lizards, starfish, crickets, snails and earthworms are among the long list of animals that can shed a part of their body to escape a predator. Scientists dub this strategy ‘autotomy.’ Sometimes the lost body part, typically a tail, regrows, although it often regrows into a stunted facsimile of the original organ. A regrown lizard tail, for example, is normally discolored and it’s strengthened with cartilage instead of bone.

That’s pretty weird. But a recent discovery pushed autotomy off the weirdness charts.

For the first time, scientists discovered that a type of mammal sheds its skin to escape predation. Its skin, people! You know, that stuff that clads muscles, organs and blood vessels to protect them from bacteria, viruses and the weather.

Scientists following up on rumors of skin autotomy by African spiny mice found what they were looking for almost as soon as they opened their traps on Kenyan rocky outcroppings.

“Handling both species in the field confirmed that vigorous movement often led to tearing of the skin,” the scientists, from the universities of Florida, Nairobi and Wyoming and the Mpala Research Centre, reported in a recent edition of Nature. “Tearing resulted in large open wounds or skin loss ranging from small pieces to areas approximating 60% of the total dorsal surface area.”

The researchers compared the might taken to tear the specimens’ brittle skin with that taken to shred the elastic skin of a more common species of mouse: It took 77 times more energy to break the skin of the common mouse than that of the spiny one.

This wound quickly healed / Courtesy: Nature

Not only did the rodents readily shed their skin — they hastily grew it back. Five out of six wounds, each 4mm apiece, that were inflicted on the poor creatures by the researchers had completely healed within three days. Compare that with the five to seven days that it takes for a common mouse’s comparable wound to heal.

With additional research into the cellular processes involved with this remarkable healing process, the scientists say the discovery could lead to the development of new ways to heal wounded humans.