A newly discovered shape-shifting frog can change skin texture based on what it is sitting on, according to a recent study published in the Zoological Journal of the Linnean Society. The frog was discovered by Katherine Krynak, a Case Western Reserve University PhD student and her husband, Tim Krynak, a projects manager at Cleveland Metroparks' Natural Resources Division.
The mutable rainfrog, or Pristimantis mutabilis, was found at Reserva Las Gralarias in north-central Ecuador, according to Science X Network. The mutable rainfrog was initially believed to be the only one of its kind, but there is another rainfrog that can change skin texture, but its ability was never reported.
Katherine thinks the shape-shifting ability provides the rainfrogs with camouflage from predators. The Krynak's first spotted the small frog (about the width of a marble) in 2009, sitting on a leaf covered in moss. They put the frog in a cap and nicknamed it "punk rocker" because of the spikes covering its body.
The next day, Katherine removed the frog from the cup and set it on a smooth white sheet of plastic, so Tim could photograph it - but the "punk" was gone. Katherine thought she grabbed the wrong frog. "I then put the frog back in the cup and added some moss," Katherine said, according to Science X Network. "The spines came back... we simply couldn't believe our eyes, our frog changed skin texture!"
"I put the frog back on the smooth white background. Its skin became smooth," she continued. "The spines and coloration help them blend into mossy habitats, making it hard for us to see them, but whether the texture really helps them elude predators still needs to be tested."
Researchers found that it takes the frogs about three minutes to change skin texture. Prismantis sobetes is a relative of P. mutabilis with similar markings that can perform the same party trick. No other relatives have been tested so far.
Other study authors include lead author Juan M. Guayasamin, from Universidad Tecnológica Indoamérica, Ecuador, Carl R. Hutter, from the University of Kansas, and Jamie Culebras, a member of Tropical Herping.
"Discovering a new species is incredible enough," Katherine said, according to the Amphibian Specialist Group (ASG). "You wouldn't think anything could top that. And then you discover that it also changes shape, suddenly growing spines that then disappear. I just kept asking 'did that really just happen?'"