When little glass frogs become nocturnal, they can become transparent, hiding almost 90 percent of their red blood cells.
Colorful areas are hidden inside the frog’s liver, which can mask cells, according to a study published Thursday in the journal. Science.
These are during the day small frogs they spend their time hanging under tree leaves. At this time, their green forms do not cast a shadow, making them largely invisible to potential predators.
When little glass frogs become nocturnal, they can become transparent, hiding almost 90 percent of their red blood cells. Above: A female glass frog is shown with eggs in her transparent ovaries, photographed from below with flash
However, after waking up, the frogs appear more reddish-brown in color.
“When they’re transparent, it’s for their safety,” said Junjie Yao, a biomedical engineer at Duke University and co-author of the study. They can actively avoid predators when they are awake, but they are “stealth-adapted” when they are asleep and most vulnerable.
Scientists have used light and ultrasound imaging technology to uncover a new insight: frogs can “concentrate” or hide almost 90 percent of their red blood cells in their livers while they sleep.
This circulating blood would otherwise give them away. Yao also pointed out that frogs can pack and compress many of their internal organs.
Juan Manuel Guayasamin, a frog biologist at the University of San Francisco in Quito, Ecuador, told The Associated Press that the study “beautifully explains how glass frogs hide blood in the liver to maintain transparency.”
Colorful areas are hidden inside the frog’s liver, which can mask cells, according to a study published Thursday in the journal Science. Above: A glass frog sits on a leaf
Scientists have used light and ultrasound imaging technology to uncover a new insight: frogs can “concentrate” or hide almost 90 percent of their red blood cells in their livers while they sleep. Above: A male glass frog photographed from below
How they managed to achieve this feat is still somewhat of a mystery.
For most animals, having too little oxygen circulating in the blood for several hours would be fatal – and concentrating the blood so tightly would result in fatal clotting. However, frogs can survive.
The researchers believe that further research on the species could inform the development of anti-clotting drugs.
“Transparency is very rare in nature, and in land animals, outside of the glass frog, it’s actually unheard of,” said Oxford University biologist Richard Whitem, who was not involved in the study.
Translucent ones include some fish, shrimp, jellyfish, worms, and insects—none of which carry large amounts of red blood in their bodies.
“It’s a really amazing, dynamic camouflage uniform,” White said.
“Transparency is very rare in nature, and in land animals, outside of the glass frog, it’s actually unheard of,” said Oxford University biologist Richard Whitem, who was not involved in the study. Above: A leaf-dwelling glass frog is seen
Above: A collection of photos by the researchers shows the same frog during sleep, under anesthesia, and active (in transmitted light), showing the difference in red blood cells in the circulatory system.
