One of the Titicaca frogs kept alive in a breeding programme at Amersfoort Zoo. Photo: Amersfoort Zoo.
It may not be the most attractive of creatures, but spotting a naked, sunbathing scrotum frog in Lake Titicaca remains a remarkable experience.
He vivid blue Lake Titicaca, on the border of Peru and Bolivia, is already a breathtaking tourist attraction in its own right. The world’s highest navigable lake is home to the floating ‘reed islands’ of the hospitable Uros people. The Uros are happy to share their traditions, take visitors out on hand-built boats, and sell their colourful woven textiles with great enthusiasm. These textiles sometimes feature the Titicaca frog, or scrotum frog (Telmatobius culeus) – a rare amphibian that owes its nickname to its heavily folded and wrinkled skin. These skin flaps function as gills, meaning the frog has little need to breathe at the surface and has traded its amphibious lifestyle for a fully aquatic existence.
SACK
The frog’s scientific name reflects its habitat: Telmatobius means ‘living in water’, from the Greek télma and bios, meaning ‘pond’ or ‘marsh’ and ‘life’ respectively. Culeus is Latin for ‘sack’, a well-known synonym for scrotum. The frogs can weigh up to a kilogram and were formerly eaten locally, owing to their supposed beneficial effects on breathing and libido. The endemic species is classified as ‘Endangered’, threatened by falling water levels, increasing pollution, fungal infections, and introduced trout that prey on their tadpoles (BioScience, 16 April).
SHORTCUT
The chances of spotting a living Titicaca frog as a tourist are slim, although they do occasionally bask in the upper layers of the water. The spawning site near the Peruvian village of Chucuito was once considered a good place to see scrotum frogs – a village that also attracts visitors because it is home to the sacred Inca Uyo, a ‘fertility temple’ lined with dozens of phallic sculptures. For biologists with flight shame or limited time, there is a shortcut: thanks to a breeding programme established by Denver Zoo, Titicaca frogs now swim in aquaria in Prague, Berlin, Vienna, and even in Amersfoort and Rhenen. Catching a glimpse of the scrotum frog is therefore within everyone’s reach.
Since 2019, the Titicaca frog has featured on a Peruvian commemorative coin worth 1 Sol. This appears to have boosted conservation efforts for these endangered frogs (Herpetology Notes, 2023).
See also:
–Column Souvenir – Bionieuws, 4 July 2025
–Titicaca water frog breeding programme – Citizen Conservation