RETICULATED GLASS FROG
No prizes for guessing how glass frogs got their name. Thin, oxygen-breathing skin is, of course, something shared by adult amphibians worldwide, but its appearance is fantastically diverse.
The glass frogs of Central and South America have gone for ultratransparency. Their blood vessels, digestive tract and other organs – sometimes even the beating heart – are clearly visible.
Being see-through probably helps these frogs evade predators, as when lit from above, their whole body picks up the colour of whatever leaf they happen to be sitting on.