Telmatobius culeus, commonly known as the Titicaca giant water frog or the Lake Titicaca frog, is an amphibian species endemic to Lake Titicaca, on the border of Peru and Bolivia. This fully aquatic, large-bodied frog performs all gas exchange through its skin.

Taxonomy and Geographic Distribution

The species Telmatobius culeus belongs to the Telmatobiidae family within the Animalia kingdom and Anura order. Its scientific name was given by Garman in 1875. The species' habitat is primarily Lake Titicaca itself and some surrounding water bodies, such as Lago Saracocha and Lago Umayo. This amphibian lives at an elevation of approximately 3,810 meters. Its geographic range extends across Peru and Bolivia, where it is considered a single threatened geographic area.

Habitat and Ecology

The Titicaca Giant Water Frog is a species that spends its entire life cycle in water. Adult frogs generally prefer muddy or sandy substrates with rocks and aquatic vegetation, while juveniles tend to prefer rocky habitats. Its diet is varied but primarily consists of snails and crustaceans. Reproduction occurs near lake shorelines, among submerged vegetation, and in shallow waters. It has been observed to breed year-round, but mating is more common in the winter months. Observations in captivity and in the wild have shown that the number of eggs laid by female frogs at a time can vary.

Threats

The species' population is rapidly declining due to various interacting threats. One of the biggest threats is the uncontrolled poaching of adults. Frogs are used both as food and in traditional medicinal products used in Peru and Bolivia as aphrodisiacs and to treat various ailments, including asthma.

Water pollution has become a problem due to the discharge of domestic, industrial, and agricultural wastewater into the lake, degrading habitat quality. Furthermore, environmental events such as hydrogen sulfide release from the lake bottom and algal blooms have caused mass mortality, particularly on the Bolivian side.

Pathogens such as chytrid fungus ( Batrachochytrium dendrobatidis ) and ranavirus, which threaten amphibians, have been detected in frogs, and there are concerns that chytrid fungus may also spread through illegal trade. Invasive species introduced to the lake, such as rainbow trout, also exert predation pressure on frog larvae.

Conservation Status and Measures

The status of Telmatobius culeus was updated to Endangered (EN) in 2020, from Critically Endangered (CR) in 2004. It is protected by national laws in both Peru and Bolivia, and all commercial hunting, capture, and export are prohibited.

International trade in the species was placed under the strictest control in 2016, with its inclusion on CITES Appendix I. Peru and Bolivia have jointly approved a Binational Plan of Action that includes priority actions for the conservation of the frog and other species.

Conservation efforts include in-situ actions, ex situ breeding, and awareness-raising projects in the Titicaca National Reserve. To address the pollution problem, both countries have undertaken initiatives to build wastewater treatment plants.