The Panamanian golden frog (Atelopus zeteki) is a critically endangered toad which is endemic to Panama. It has been considered a subspecies of A. varius, but is now generally regarded as a separate species. While the IUCN still lists it as critically endangered, it may have been extinct in the wild since 2007. Individuals have been collected for breeding in captivity in a bid to preserve the species. Although known as a frog, the golden frog, despite being smooth-skinned and frog-like in appearance, is classified as a "True toad" (Bufonidae). Like other frogs and toads, the golden frog is capable of secreting poison to help protect themselves from predators. In the case of the golden frog, this is a water-soluble neurotoxin called zetekitoxin. In dry habitat, the adult male measures 35 millimetres (1.4 in) to 40 millimetres (1.6 in) and weighs 3 grams (0.11 oz) to 5 grams (0.18 oz). The adult female ranges from 45 to 55 mm and from 4 to 7 g. It is larger in wet forests, where the male can grow to 48 mm and weigh up to 12 g, and the female can be as large as 63 mm and weigh up to 15 g. They inhabit tropical forest regions, particularly on mountains, near streams.