If you tried to grab a Geckolepis megolepis gecko, it would likely slip from your hand — leaving only its scales in your grasp.
Geckolepis megolepis is the newest and largest-known member of the world’s fish-scaled geckos, according to a formal description published Tuesday in PeerJ. Like other lizards or salamanders, these geckos can drop their tails after being caught by predators, but they can also escape capture thanks to break-away skin.
“It is remarkably easy” for the scales to become dislodged, said herpetologist Mark Scherz, who led the study at Zoologische Staatssammlung, München in Germany. “It is hard to catch these geckos without some scales coming off,” he added.
Scherz and his colleagues learned that firsthand when they started studying the lizards in their native home of Madagascar, where the other four species of Geckolepis reside. Even though the researchers tried a passive trapping technique of luring the geckos into bags, most ended up losing a few of their scales.
All Geckolepis geckos have tear-away skin, as do a handful of other gecko species. The animals lose their scales as a defense mechanism.
“A predator grabs them, they spin, ripping their own skin off,” Villanova University herpetologist Aaron Bauer, who was not involved in the study, said. “Then this little naked pink gecko runs away while the predator is left chewing on these fishlike scales.”
They’re left naked, but alive. The scales take two to three weeks to grow back, Scherz said. However, scientists don’t completely understand how the process of regeneration occurs. In the meantime, the geckos are soft, slimy and vulnerable. Scherz said that the animals might find a dark, damp place to hide until their scales grow back.
The maneuver is also costly because of the calories and energy burned to constantly shed and regrow body parts like scales and skin. Most geckos have velvety skin made of tiny scales. But G. megolepis has larger scales than any other gecko species, both in terms of absolute size and relative to body size.
“But even if that cost is high, it’s still not as high as being eaten,” Scherz said. “It’s a good strategy to escape.”
Madagascar is home to a wide variety of geckos, from leaf-tailed geckos and fish-scaled geckos to several tiny species. However, it is becoming increasingly difficult to catalog these animals in the face of habitat destruction in Madagascar.
“In a way this is sort of a continuation of this trend,” Bauer said. “We find more and more interesting species there — at the same time as there’s less and less habitat.”