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Golden Toad And Poison Dart Frog

Three hypotheses of how the chytrid fungus could have caused the extinction of the golden toad were reviewed by Rohr et al.

formerly known as poison arrow frog) is the common name of a group of frogs in the family Dendrobatidae which are native to tropical Central and South America. These species are diurnal and often have brightly colored bodies. This bright coloration is correlated with the toxicity of the species, making them aposematic. Some species of the family Dendrobatidae exhibit extremely bright coloration along with high toxicity, while others have cryptic coloration with minimal to no amount of observed toxicity.

 

Male golden toad image

Male golden toad

Golden toad

formerly Bufo periglenes) is an extinct species of true toad that was once abundant in a small, high-altitude region of about 4 square kilometres (1.5 sq mi) in an area north of the city of Monteverde, Costa Rica. It was endemic to elfin cloud forest.
The last sighting of a single male golden toad was on 15 May 1989, and it has since been classified as extinct by the International Union for Conservation of Nature (IUCN).

Poison dart frog

The species that have great toxicity derive this from their diet of ants, mites and termites.Other species however, that exhibit cryptic coloration and low to no amounts of toxicity, eat a much larger variety of prey. Many species of this family are threatened due to human infrastructure encroaching the places they inhabit.

These amphibians are often called “dart frogs” due to the Amerindians’ indigenous use of their toxic secretions to poison the tips of blowdarts. However, of over 170 species, only four have been documented as being used for this purpose (curare plants are more commonly used), all of which come from the genus Phyllobates, which is characterized by the relatively large size and high levels of toxicity of its members.

Toxicity and medicine

About 28 structural classes of alkaloids are known in poison frogs. The most toxic of poison dart frog species is Phyllobates terribilis. It is argued that dart frogs do not synthesize their poisons, but sequester the chemicals from arthropod prey items, such as ants, centipedes and mites – the diet-toxicity hypothesis.
Because of this, captive-bred animals do not possess significant levels of toxins as they are reared on diets that do not contain the alkaloids sequestered by wild populations. In fact, new studies suggest that the maternal frogs of some species lay unfertilized eggs, which are laced with trace amounts of alkaloids, to feed the tadpoles.

This behavior shows that the poisons are introduced from a very young age. Nonetheless, the captive-bred frogs retain the ability to accumulate alkaloids when they are once again provided an alkaloid-containing diet. Despite the toxins used by some poison dart frogs, some predators have developed the ability to withstand them. One is the snake Erythrolamprus epinephalus, which has developed immunity to the poison.

Chemicals extracted from the skin of Epipedobates tricolor may be shown to have medicinal value. Scientists use this poison to make a painkiller. One such chemical is a painkiller 200 times as potent as morphine, called epibatidine; however, the therapeutic dose is very close to the fatal dose. A derivative ABT-594 developed by Abbott Laboratories, called Tebanicline got as far as Phase II trials in humans, but was dropped from further development due to unacceptable incidence of gastrointestinal side effects.(Wikipedia)

Golden toad Description

The golden toad was one of about 500 species in the family Bufonidae—the “true toads”. Males were orange and sometimes slightly mottled on the belly, while females showed a greater variety of colors, including black, yellow, red, green, and white; both sexes had smooth skin.

While males had brilliant orange that attracted females to mate, females are covered with a dark, charcoal colored outlined with yellow lines. Sexual dimorphism played a key role in identifying females, who were typically larger than males. Body length ranged from 39 to 48 mm in males and from 42 to 56 mm in females. Males had proportionally longer limbs and longer, more acute noses than females.Females also had enlarged cranial crests above the level of the orbit (eye socket), while in males the crests were much lower.

Individuals spent the majority of their lives in moist burrows, in particular during the dry season. The average lifespan of the golden toad is unknown, but other amphibian species in the family Bufonidae have an average lifespan of 10–12 years.

 

Facts For Kids Golden Poison Frog

P. terribilis (frog)

considered to be one of the most intelligent anurans. Like all poison dart frogs, captives can recognize human caregivers after exposure of a few weeks. They are also extremely successful tongue hunters, using their long, adhesive tongues to catch food, and almost never miss a strike. This success at tongue-hunting implies better brainpower and resolution of eyesight than some other frogs. Golden poison frogs are curious, bold, and seemingly aware of the fact that they are next to invulnerable, making no attempt to conceal themselves and even flaunting their striking colours to intimidate potential predators.

Goldener Giftfrosch image

Goldener Giftfrosch image

Golden poison frogs are social animals. Wild specimens typically live in groups of four to seven (average six); captive frogs can be kept in groups of 10 or even 15, although groups that rise past that number are extremely susceptible to aggression and disease. Like all poison dart frogs, they are rarely aggressive towards members of their own species; however, occasional minor squabbles may occur between members of the group. Being immune to their own poison, golden poison frogs interact constantly with each other. They communicate not only with their calls, but also with gestures. Push-up movements are a sign of dominance, while lowered heads seem to signal submission.

P. terribilis frogs are dedicated parents. The golden poison frogs lay their eggs on the ground, hidden beneath leaf litter. Once the tadpoles emerge from their eggs, they stick themselves to the mucus on the backs of their parents. The adult frogs carry their young into the canopy, depositing them in the pools of water that accumulate in the centre of bromeliads and water-filled tree holes. The tadpoles feed on algae and mosquito larvae in their nursery. After metamorphosis is complete, parent frogs lead the froglets to an existing group.

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