Freaky Frogs

Lake Titicaca Frog

A Lake Titicaca frog in a tank
Image Source: Petr Hamerník

Two weeks ago, I wrote a brief introduction to the world of freaky frogs. But back then, we barely scratched the surface. Today, we’re well and truly diving into the deep end – of Lake Titicaca to be precise. Covering 8,372 km², straddling the border between Peru and Bolivia, this is the largest lake in South America. And, at 3,812 m above sea level in the Andes Mountains, it’s also the world’s highest commercially navigable lake. Due to its high altitude, the water in Titicaca is rather deficient in oxygen – but the lake’s most famous inhabitant, the strange-looking Lake Titicaca frog, manages to thrive despite this.

When this frog was first described in 1876, it was given the scientific name Telmatobius coleus, which roughly translates to ‘aquatic scrotum’. Today, it is popularly known as the ‘scrotum frog’. An unflattering name, perhaps, but one that is somewhat justified. That’s because the Lake Titicaca frog has an abundance of loose, baggy skin that falls into folds around its back, legs, and everywhere in between, giving it a rather wrinkled and unsightly appearance. But it is precisely this baggy cloak of skin that allows the Lake Titicaca frog to cope with the oxygen-poor waters of its home.

One of the world’s most aquatic frogs, this species has small lungs and rarely uses them to breathe. Instead, it relies primarily on diffusion through its moist, permeable skin to obtain the oxygen it needs. The creased, ruffled design of its skin maximises the surface area needed for diffusion, allowing this amphibian to make the most of the limited quantity of oxygen dissolved in the lake’s water. In essence, its whole body acts as one giant gill. The ratio of surface area to body volume is maintained throughout the frog’s life – the larger it grows, the more exaggerated its pleats and folds become, to keep up with the amphibian’s greater respiratory demands. This wrinkly wonder even does press-ups on the lake bed to increase the flow of water around its body, enhancing the absorption of oxygen even further.

Inside the frog’s body, further adaptations have been made to ensure that as much oxygen as possible is transported to each and every cell. The red blood cells that transport gases around its body not only contain the most oxygen-carrying haemoglobin of any amphibian – they’re also the smallest. This means that the red blood cells can be packed more tightly within the frog’s blood vessels, allowing more oxygen to be shunted around the body to supply the animal’s demands. In addition, the Lake Titicaca frog has the lowest known metabolic rate of any frog, which helps to conserve the oxygen that it has efficiently harvested.

A Lake Titicaca frog in water, with its loose, baggy skin billowing around it
In the water, with its strange whorls of loose skin puffed up around it, the Lake Titicaca frog almost looks as though it is trapped inside a sack.

However, just like many other frogs and toads around the world, the Lake Titicaca frog is now an endangered species. Found only in and around its namesake high-altitude lake, this frog may have learned to cope with a deficiency of oxygen, but it hasn’t yet learned how to cope with local people. Many Lake Titicaca residents live on floating reed beds and use the frogs for a variety of reasons, including as a protein-rich snack and something of a cure-all. Small specimens can be swallowed whole to supposedly cure a fever, while bigger ones are sometimes strapped to a fractured limb to act as a living poultice. Meanwhile, dishes with Titicaca frogs are also sold by some local restaurants as a novelty to tourists.

But, perhaps most famously, this frog can also be turned into a rather grisly beverage. After the skin of the dead frog has been removed, it is placed into a container with some honey, water, and a local tuber (maca), which is then all blended together. Drinking this ‘frog juice’ (or Jugo de Rana, as it’s referred to in Spanish) is said to cure a wide range of ailments, including bronchitis, tuberculosis, asthma, and even impotence. As such, this concoction has been dubbed the ‘Peruvian Viagra’.

Of course, there’s no scientific evidence to suggest that the ‘scrotum frog’, liquefied or otherwise, holds any of the elixir-like benefits it’s supposed to possess. However, such long-lasting traditions don’t die as easily as the frogs themselves. We often hear about large, endangered mammals such as rhinos being hunted for body parts that are falsely believed to harbour medicinal properties, but it’s a sad fact that many smaller, more obscure and less charismatic animals around the world, such as the Lake Titicaca frog, share a similar plight.

In the next Freaky Frogs article, we’ll be moving from the ‘scrotum frog’ to the ‘Wolverine frog’ – a species that can force some of its own bones out through its skin to defend itself.


  • Jason Woodcock

    With a background in conservation and animal behaviour studies, Jason's passion lies in the natural world. He adores all things nature and enjoys nothing more than spotting rare and interesting species out in the wild. He has also worked in a zoo and knows plenty about keeping the animals inside our homes healthy and happy, too.

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