Glass frog
Centrolenidae
nearly 90%
of red blood cells hidden in the liver
Glass frogs live in Central and South American forests and sleep on the undersides of large leaves. While they rest, their skin and muscles become nearly transparent, so light passes through and they blend into the green leaf beneath them.
Red blood cells absorb light and would give them away. Researchers at Duke University and the American Museum of Natural History found that a sleeping glass frog pulls nearly 90 percent of its red blood cells out of circulation and packs them into its liver. When it wakes, the cells flow back out, and nobody yet knows how it avoids a giant blood clot.
Imagine packing most of your blood into one organ for a nap, then releasing it with no clots.
