Glass Frogs Become Translucent

One of the most compelling examples of design in natural things is a frog that escapes predators by making itself practically invisible. During the day, glass frogs (Hyalinobatrachium Fleischmanni) can be up to 61% transparent while sleeping on green leaves in their native Central and South America. At night, they regain their color and become active. Medical researchers want to know how they do this because it might give a clue about how to avoid blood clotting in humans.

Somehow, glass frogs separate their red blood cells from the blood plasma. The plasma is still circulating, and if you look closely, you can see the heart beating. But the red blood cells are temporarily stored in the liver, making the frog transparent enough to avoid notice by predators. When the frog becomes active, its color returns, and, like most frogs, it can evade predators.

Jesse Delia, a researcher at the Museum of Natural History in New York, and Carlos Taboada of Duke University have used ultrasound imaging technology to understand what the glass frogs are doing. They found that the frogs store their red blood cells in the liver, enlarging it by 40%.

The challenges the glass frogs are able to overcome include having little or no oxygen while avoiding blood clotting. That is what the medical researchers want to understand because the application to anti-blood-clotting medications could be significant.

God has built many techniques for survival into living things, and this is one of the most interesting. We continue to learn from the things God has made.

— John N. Clayton © 2023

Reference: BBC News and the journal Science