Frog, Panamanian Golden


Atelopus zeteki


Adult male length: 1.4 – 1.6 in (35 – 40 mm); adult female length: 1.8 – 2.2 in (45 – 55 mm); weight: 0.1 – 0.25 oz (3 – 7 g); appearance: head is longer than broad, with a pointed, protuberant snout and rounded canthus rostralis; pupil is horizontally elliptical; body is slim with long limbs, and the upper surface is smooth with minute spicules; fingers are elongate and narrow; toes are extensively webbed with only toe IV substantially free of webbing; adult coloration: uniform golden yellow with one to several large black dorsal markings; abdomen is yellow, except when a female is carrying eggs, then the ventral surface is lighter-colored; tadpoles (at least in captivity) are completely white for the first few days post-hatching, developing pigmentation after a few days.

Family

Bufonidae

Order

Anura

Class

Amphibia

Range

Panama

Habitat

Tropical forest regions, particularly on mountains, near streams

Life Expectancy

Up to 5 years in captivity

Sexual Maturity

Unknown

Diet

In the wild, they eat small invertebrates; in the Zoo, they are fed small crickets and fruit flies.

Status

IUCN – Critically Endangered; CITES – Appendix I

Behaviors

Panamanian golden frogs are terrestrial, diurnal forest frogs that generally occur near rapid-flowing small streams. Occasionally males are heard calling in the forest far from the water, more than 164 ft (50 m) away. These frogs move by a distinctive ambling walk, and consume a variety of small invertebrates. In wet forest stream habitats, the frogs are dispersed in and along streams. They can climb and are found up to 9.8 ft (3 m) above ground, perching on large moss-covered boulders near waterfalls and along the banks of streams. In contrast, in dry forest stream habitats the frogs are smaller (2/3 the size), distributed mainly over the forest floor, and occur only up to 4.9 ft (1.5 m) above ground. The population density of Panamanian golden frogs is higher in dry forests than in wet forests. Female frogs move into the forests in the late dry and early rainy season (February-March) and return to streams to breed in the late rainy and early dry season (November-January). Males tend to stay in streams year-round establishing territories and waiting for the females to return. Male frogs perch on rocks in or along the banks of streams and waterfalls, and they defend their territory by semaphoring (hand-waving, plus an unusual form of foot-raising—not foot-flagging, and reorientation). Males also vocalize, but prefer semaphoring over vocalization, apparently due to the noisiness of waterfalls and stream flow in their natural habitat. Females also semaphore in this species, as they do in the related species Atelopus varius. There is a male-favored gender bias, resulting in the majority of males being single, and thus all females encountered in streams are amplexed. Amplexus can last from a few days to two months in captivity. Females deposit large clutches of eggs. The eggs are laid in long strands encased in a protective gel, and a single egg clutch can number as many as 900 eggs. The eggs are light- sensitive and are laid underwater in dark crevices. Interestingly only the female leaves the egg-laying site, while the male takes care of the clutch. It defends “its” puddle of water for the next three to four weeks against all other frogs. When the tadpoles hatch after this time, it carries its young, if the need arises (e. g. when the puddle threatens to dry out) to another water body. Tadpoles feed on diatoms and algae found in the stream. Golden frogs remain in the tadpole stage for a period of 120-240. Tadpoles are commonly found resting on top of stones and stream gravel at the edges of shallow pools below cascades. They may live anywhere along the stream where water pools, as long as the pool is directly connected to flowing channels. They prefer water depths of 1.9 – 13.8 in (5-35 cm). The development of the larvae takes place with the onset of the wet season, and the possession of a large ventral adhesive disc allows the larvae to remain attached to objects on the bottom of the stream against the torrential current. It has been observed that the ventral suctatorial disc of newly hatched Atelopus zeteki larvae is either undeveloped or not yet functional immediately upon hatching, and it is not known at what point the disc acquires functionality. The golden frog appears to socialize with other frogs using sounds from the throat and hand waving. This hand waving was investigated by a group of amphibian experts and appears to be used for a variety of social situations, from friendly waves to signals to back off. A fake frog with a moving hand was used, and after repeated hand waving, the authentic frog attacked. Juveniles were always observed within 6.6 ft (2 m) of the stream. Interestingly, although adult males are territorial and do not allow conspecifics other than gravid females to approach, researchers have observed subadults in close proximity and sometimes even touching adult males. However, as soon as significant rainfall began, all juveniles vanished from open streamside areas used by adult males.

Adaptions

The golden frog is capable of secreting poison to help protect itself from predators. The poison is a water-soluble neurotoxin called zetekitoxin. This is the most toxic species of Atelopus, with the skin of a single individual containing enough toxins to kill 1,200 20g mice. Zetekitoxin AB, the major alkaloid in Atelopus zeteki’s skin extracts, is an analog of saxitoxin and an extremely potent blocker of voltage-dependent sodium channels. Atelopus zeteki is currently the only known amphibian with saxitoxin-analog activity, producing zetekitoxin C in addition to zetekitoxin AB. It has been hypothesized that zetekitoxin production requires the presence of symbiotic bacteria, as various forms of bacteria (marine, anaerobic, and cyanobacteria) are known to produce saxitoxin. The humidity in Panama’s primeval forest during the rainy season in summer is so high that the Golden frog during its evolution became completely independent from permanent water bodies as basis for reproduction and the development of the tadpoles. It chooses as “nurseries” holes in branches, or trees, filled with water or other small temporary puddles. Courtship amongst Panamanian golden frogs involves communication by a form of semaphore, waving at rivals and prospective mates, in addition to the sounds more usual among frogs. This adaptation is thought to have evolved in the golden frog because of the noise from the fast-moving streams of their natural habitat, which may drown out vocalizations.

Special Interests

This beautiful frog was named after the American insect scientists James Zetek (1886 - 1959), first director of the Barro Colorado Island (BCI) research station in Panama. The Panamanian golden frog is something of a national symbol, appearing on state lottery tickets. In 2010 the Panamanian Government passed legislation recognizing August 14 as National Golden Frog Day. This species is protected in Panama by national legislation (as Atelopus varius zeteki) decree No. 23 of January 30, 1967. Pre-Colombian indigenous peoples of the distant past revered the golden frog. They crafted gold and clay talismans in a variety of forms (frogs, people, jaguar) known to contemporary Panamanians as huacas/huacos. Caches of buried huacas are sought and unearthed by fervid amateur archeologists called “huaqueros” and are sold at exorbitant prices to collectors of antiquities. Replicas are commonly found in jewelry stores in Panama. This species appears to undergo an ontogenetic change in color, from cryptic green and black coloration in new and recently metamorphosed frogs and juveniles, to aposematic bright yellow, or yellow and black, in subadults and adults. Lindquist and Hetherington (1998b) hypothesized that this may parallel the acquisition of skin toxicity. They reported that metamorphs and young juveniles were secretive, unlike the adults which moved about openly.

Folklore

Local legend holds that chieftains of the Guaymí tribe would ascend the Pacific slope to the mountains of Gaital, Pajita, and Caracoral (in El Valle de Antón) annually as a sacred rite. This legend evolved into the myth that the golden frog would transform into gold huacas upon death. Hence, anyone seeing or possessing the frog alive would have good fortune (buena suerte) visited upon them.

Conservation

Listed as Critically Endangered because of an observed drastic decline in population and extent of occurrence, estimated to be more than 80% over the last ten years, probably due to chytridiomycosis. This species was reasonably common at a number of localities, and has been recorded as recently as 2005, but it is apparently less abundant north of El Copé, in comparison with observations in 1980. It is very rare or extinct on Cerro Campana. It has been extinct in the El Valle de Antón for approximately 40 years. In recent years, populations have been declining catastrophically due to chytridiomycosis, and the well-known El Copé population collapsed and disappeared over the course of a few months in late 2004. The chytridiomycosis epidemic appears to be spreading from west to east through Panama, and populations in the eastern part of its range are now at severe risk of disappearing. The species was filmed for the very last time in the wild in 2007 by the BBC Natural History Unit for the series Life in Cold Blood by David Attenborough. The remaining few specimens were taken into captivity and the location of filming was kept secret to protect them from potential poachers. It is also threatened by collection for local zoos and hotels, illegal pet trading, deforestation, and habitat alteration by logging and farming. Project Golden Frog is an ongoing conservation consortium which connects the Republic of Panama and the United States in an effort to ensure the survival of this species. Plans for captive breeding in Panama are being supported by Project Golden Frog. Captive breeding programs for this species are already in place at a number of zoos, including the Jacksonville Zoo and Gardens in Florida, Maryland Zoo in Baltimore, the Houston Zoo, the Denver Zoo, the Detroit Zoo, and the Oakland Zoo.

Jacksonville Zoo History

This endangered species has been part of our animal collection since 2003 and we have successfully produced offspring.

Exhibit

Amphibian Conservation Center