Species: Frogs of the family Centrolenidae

Range: Rain forests of Mexico, Central America, and South America

Weird Feature(s): Translucent skin, plasma globe eyeballs, daddy issues

We’ve covered some pretty odd frogs on Miracles of Weird. First we had the horror frog, a frog that breaks a bone in its own finger, forces the bone chard through its skin, and shanks its enemies with it. Then we had the Emei mustache toad, a toad who grows a seasonal set of mustache spikes to do battle with rival males. But none of these have afforded us what we’ve really always wanted – a full visual of their heart, liver, and gastrointestinal tract.

Elke Vockenhuber

Frogs of the family Centrolenidae are known as “glass frogs,” and one look at them will tell you why. Their skin is almost entirely transparent all over their body, especially on their underside, where their liver, heart, lungs, and intestines can be viewed with amazing clarity. High school biology teachers take note – this could be a way to study the organs of a frog without actually taking the scalpel to it.

Since those pesky internal organs aren’t transparent and thus can’t afford the frog complete invisibility, some species of glass frog have evolved the ability to alter what little green pigment they have to blend in perfectly with the leaf they are resting on.

 The ghost glass frog is an especially interesting species. It is called the ghost glass frog because of how well it can mimic the color of whatever leaf it’s sitting on. Probably still pretty easy to spot those plasma ball eyes, though. (Mudfooted)

Glass frogs lay their eggs on the underside of leaves that are hanging over water; That way, when the tadpoles hatch, they simply drop into the water and begin their anatomical journey towards froghood. The males of the Hyalinobatrachium fleischmanni species of glass frog look after the eggs for about 19 days, being sure to keep them wet as they develop. Recent studies have shown that when H. fleischmanni daddies decide to skip town, the developing embryos respond in an interesting way. Once the eggs are laid, the males have to decide between sticking around and protecting them and going out to make more fertilized eggs with somebody else. Researchers found that when daddy was out of the picture, the eggs hatched earlier. They suspect that the developing tadpoles may sense that their eggs are getting drier, causing them to jump ship.

Jesse RJ Delia

HT: Mudfooted, ScienceMag.com