Cricket glass frogs (Hyalinobatrachium colymbiphyllum), like the one pictured above, can be uncommonly found in the dense tropical forests of Costa Rica, Panama, and Columbia. Sexually dimorphic, the oviparous females are often times larger than their male suitors. Photo © Brian Gratwicke

Amphibians—by the nature of their anatomy—are exposed, fragile creatures. And this factoid is only echoed by the “canary in the mind shaft” role they’ve adopted in their endemic ecosystem—the first signs of environmental trouble are often mirrored by sharp declines in amphibian populations. But to be entirely transparent holds an entirely different connotation. And on that note, ladies and gentlemen, may I introduce to you the family of anurans that leaves nothing to the imagination—the glass frogs (Centrolenidae).

Arboreal in nature, glass frogs only descend to reproduce during the moister reproductive season. Photo © Brian Gratwicke

Arboreal in nature, glass frogs only descend to reproduce during the moister reproductive season. Photo © Brian Gratwicke

Inhabiting much of Central and South America, glass frogs comprise of three subfamilies, totaling eleven distinct genera of anurans. To date, fifty or so species have been recognized under the transparent family. And given the paraphelitc relationship of these genera—those being Centrolene, Cochranella, Hyalinobatrachium, Nymphargus—a completely new taxonomy has been proposed to the scientific community.

These white-spotted (Sachatamia albomaculata) are seen practicing the means of external fertilization commonly seen in glass frogs—amplexus. Noted by the male grasping his selected female with his two front forelimbs, he then goes about fertilizing the eggs that she simultaneously lays. Photo © Santiago Ron

These white-spotted (Sachatamia albomaculata) are seen practicing the means of external fertilization commonly seen in glass frogs—amplexus. Noted by the male grasping his selected female with his two front forelimbs, he then goes about fertilizing the eggs that she simultaneously lays. Photo © Santiago Ron

Rather petite, averaging only five centimeters in length, glass frogs inhabit the arboreal canopies of their endemic ranges. And when breeding season nears, they’ll descend from their high-roosted dwelling, gathering near river systems. It’s at this time that the territorial males will begin their melodious mating ritual—each species emits a distinctly-pitched vocalization to attract sexually mature females of their own kin. In fact, it’s been documented that mature males will often use the boney projection from their humerous to fend-off encroaching males. How do we know this—scar tissue from the losers. Once mated and eggs externally fertilizes by the side of a moist, rocky surface, females may stay with their unborn young for a few days before abandoning them. And, should external predatory forces remain at bay; a new generation of “stained glass-like” amphibians will drop into the body of water that they’ve been laid over.

All great art can be traced back to an organic contribution. From the foliage hues in a foreground, the visually appealing Fibonacci sequences, natural curve, etc., all these organic mediums echo one characteristic—beauty. It’s all around us, all the time. And the glass frogs we share this planet with are those vividly-embellished, chromatic mosaics.

By Matt Charnock