Poison Dart Frog

**Poison dart frog** (also known as **dart-poison frog**, **poison frog** or 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 brightly colored species, making these species aposematic. Some species of the Dendrobatidae family exhibit extremely bright coloration along with high toxicity, while others have cryptic coloration with minimal to no amount of observed toxicity. 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.

## Characteristics

Most species of poison dart frogs are small, sometimes less than 1.5 cm (0.59 in) in adult length, although a few grow up to 6 cm (2.4 in) in length. They weigh 1 oz. on average. Most poison dart frogs are brightly colored, displaying aposematic patterns to warn potential predators. Their bright coloration is associated with their toxicity and levels of alkaloids. For example, frogs of the genus *Dendrobates* have high levels of alkaloids, whereas *Colostethus* species are cryptically colored and are not toxic.

Poison dart frogs are an example of an aposematic organism. Their bright coloration advertises unpalatability to potential predators. Aposematism is currently thought to have originated at least four times within the poison dart family according to phylogenetic trees, and dendrobatid frogs have since undergone dramatic divergences – both interspecific and intraspecific – in their aposematic coloration. This is surprising given the frequency-dependent nature of this type of defense mechanism.

Adult frogs lay their eggs in moist places, including on leaves, in plants, among exposed roots, and elsewhere. Once the eggs hatch, the adult piggybacks the tadpoles, one at a time, to suitable water, either a pool, or the water gathered in the throat of bromeliads or other plants. The tadpoles remain there until they metamorphose, fed by unfertilized eggs laid at regular intervals by the mother.

## Habitat

Poison dart frogs are endemic to humid, tropical environments of Central and South America. These frogs are generally found in tropical rainforests, including in Bolivia, Costa Rica, Brazil, Colombia, Ecuador, Venezuela, Suriname, French Guiana, Peru, Panama, Guyana, Nicaragua, and Hawaii(introduced).

Natural habitats include subtropical and tropical, moist, lowland forests, subtropical or tropical high-altitude shrubland, subtropical or tropical, moist, montanes and rivers, freshwater marshes, intermittent freshwater marshes, lakes and swamps. Other species can be found in seasonally wet or flooded lowland grassland, arable land, pastureland, rural gardens, plantations, moist savanna and heavily degraded former forest. Premontane forests and rocky areas have also been known to hold frogs. Dendrobatids tend to live on or close to the ground, but also in trees as much as 10 m (33 ft) from the ground.

## Research

Scientists are unsure of the source of poison dart frogs' toxicity, but it is possible they assimilate plant poisons which are carried by their prey, including ants, termites and beetles. Poison dart frogs raised in captivity and isolated from insects in their native habitat never develop venom. The medical research community has been exploring possible medicinal uses for some poison dart frog venom. They have already developed a synthetic version of one compound that shows promise as a painkiller.