He placed them in a Petri dish and saw each frog's circulatory system through its translucent skin — "red with red blood cells." But when he came back later, the frogs were sleeping and the ...

As tiny glass frogs fall asleep for the day, they take almost 90 percent of their red blood cells out of circulation. The colorful cells cram into hideaway pockets inside the frog liver ...

Using light and ultrasound imaging technology, the researchers discovered the secret: While asleep, the frogs concentrate, or “hide,” nearly 90% of their red blood cells in their liver.

“Red blood cells also absorb a lot of light, and we found that the frog can actually hide them by packing them into the liver.” Many aquatic creatures, like krill and salps, are see ...

But for glass frogs and other invertebrates, the greatest challenge to translucency is their red blood cells, which naturally absorb light. Until recently, in fact, precisely how glass frogs wove ...

When tiny glass frogs turn in for the night, they're able to become transparent by hiding almost 90 percent of their red blood cells. The colorful areas are tucked away inside the frog's liver ...

Using light and ultrasound imaging technology, the researchers discovered the secret: While asleep, the frogs concentrate, or “hide,” nearly 90% of their red blood cells in their liver.

Left: Sleeping glass frogs visible through a leaf. Right: A sparse population of red blood cells zooming around a sleeping glass frog’s circulatory system. (Jesse Delia & Carlos Taboada ...

"Using photoacoustic imaging to track red blood cells in vivo, we show that resting glass frogs increase transparency two- to threefold by removing [about] 89% of their red blood cells from ...

which frogs manage to avoid by storing and releasing around 90 per cent of their red blood cells into their livers on a regular basis. "There are more than 150 species of known glass frogs in the ...

"We'd let the frog rest, then poke it a few times, and let it fall asleep again." Johnsen said. Following the hemoglobin revealed that glassfrogs pull 89% of their red blood cells from circulation ...