In the cold, dark depths of Lake Titicaca, the world's largest aquatic frog floats peacefully — until bugs invade. Then those wrinkled folds of skin ripple with fury and ARC-TRAJECTORY grenades fly in every direction. The deep fights back!
The Titicaca water frog (Telmatobius culeus) absorbs all of its oxygen through its skin — it has virtually no functional lungs. To maximize surface area, it has evolved enormous folds of loose skin that hang like a baggy suit.
Living at 3,800 meters above sea level in Lake Titicaca on the Peru-Bolivia border, these frogs cope with low oxygen levels by having extremely high concentrations of red blood cells and efficient skin breathing.
To increase oxygen absorption when the water is still, Titicaca water frogs do a peculiar bob — they bounce up and down to create water flow around their skin. This 'aerobic dance' increases oxygen uptake dramatically.
These extraordinary frogs are Critically Endangered due to water pollution, over-harvesting for 'frog juice' (a local aphrodisiac drink), trout introduction, and climate change altering lake conditions. Thousands die in mass mortality events.