Have you ever looked at some animals and marvelled at how perfectly camouflaged they are? How they have adapted to perfectly blend into their habitat, whether it be leaf, tree, stick or water? Well I have, and it’s pretty impressive. But what’s even more impressive is the ultimate camouflage. This of course being to be completely see-through. If you’re transparent, you blend into any background, any habitat and are pretty much invisible. When I first heard of glass frogs, that’s what I pictured. A frog that was completely see-through, and thus, for all intents and purposes, invisible.
Although this isn’t exactly the case, it is true that parts of the glass frog are transparent. Mostly they are coloured like leaves, but they do have some translucent skin. If you look closely at the underside of a glass frog, you can see the beating heart, lungs and other organs. Which is pretty cool, if you ask me. You don’t even have to dissect the frog to see inside it! Just think of how much less exciting biology class would be if every animal were like a glass frog.
Glass frogs are tiny; males are about two centimetres long while females are a bit bigger, growing to three centimetres. They are in fact, so small and so delicate that rain can be deadly to them. Glass frogs usually are active at night, so the rain can prevent their skin from drying out. But there is danger in this strategy. A single well-placed raindrop can kill one of these tiny (and let’s face it, wussy) frogs. If I were a glass frog, I’d be pretty freaking scared to go out in the rain.
Another unusual thing about some glass frogs has to do with reproduction. More specifically with guarding and caring for eggs. Females lay the eggs on the undersides of leaves, where the eggs stick and are guarded by the male. Part of the male’s duties include preventing the eggs from drying out, and he does this using a rather unconventional tactic: he urinates on them. He will also eat any eggs that are infected with parasites, to prevent spread to the rest of the clutch. Though his methods are undoubtedly unpleasant and his children clearly will suffer from deep emotional scarring, you’ve got to give this poor dad some props for creativity.
Male glass frogs are territorial, and display by ‘croaking’, though in the case of the glass frog they are so small that the manly croaking we associate with frogs instead comes out as a tiny peeps, sometimes described as the sound a crystal glass makes. If this doesn’t works these manliest of frogs engage in a competition of strength; they do four-legged push ups at each other. If that doesn’t convince you that these mighty frogs are true men, I don’t know what will.
Glass frogs must live pretty fearful lives. If a drop of rain can kill them, just think of what other dangers they’d have to avoid. But they do have the advantage of being that one step closer to the ultimate disguise. Another couple of years and maybe glass frogs will become completely transparent and thus impossible to find or study. That would be amazing.