WASHINGTON (AP) — A species of glass frogs found in South and Central America has the rare ability to turn on and off its transparent appearance. Researchers report Thursday in the journal Science that some sleeping glass frogs concentrate, or “hide,” nearly 90% of their red blood cells in their liver. Because they have transparent skin and other tissues, it’s the blood circulating through their bodies that would otherwise give them away. When the frogs are awake and active, they become opaque. Only a few animals are naturally transparent, mostly ocean dwellers. The trick of turning on transparency while sleeping and vulnerable to predators appears to be unique to the frogs.
Glass act: Scientists reveal secrets of frog transparency
