The Brazil-nut poison frog (''Adelphobates castaneoticus'') is a species of

frog A frog is any member of a diverse and largely Carnivore, carnivorous group of short-bodied, tailless amphibians composing the order (biology), order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-f ...

in the family

Dendrobatidae 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 (biology), family Dendrobatidae which are native to tropical Central and South America. T ...

. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the state of

Pará Pará is a Federative units of Brazil, state of Brazil, located in northern Brazil and traversed by the lower Amazon River. It borders the Brazilian states of Amapá, Maranhão, Tocantins (state), Tocantins, Mato Grosso, Amazonas (Brazilian state) ...

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

. The frog is believed to have received its common name from the fact that its tadpoles sometimes develop in the hard capsules of the

Brazil nut The Brazil nut (''Bertholletia excelsa'') is a South American tree in the family Lecythidaceae, and it is also the name of the tree's commercially harvested edible seeds. It is one of the largest and longest-lived trees in the Amazon rainforest. ...

tree, which are common in its range. The nuts fall to the forest floor where they are broken open by

agouti The agouti (, ) or common agouti is any of several rodent species of the genus ''Dasyprocta''. They are native to Middle America, northern and central South America, and the southern Lesser Antilles. Some species have also been introduced else ...

s and other animals seeking the seeds, and empty husks fill with water.

Description

The Brazil-nut poison frog is a very small frog with a snout-to-vent length of ; females are usually larger than males. The

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal co ...

surface is of a shiny black colour with spots and markings of white or various shades of yellow. There is a bright yellow or orange spot where the foreleg joins the body and two more similarly coloured spots on either side of the knee joint on the hind leg, which combine to make a single large spot when the animal is stationary. A further spot on the underside of the

calf Calf most often refers to: * Calf (animal), the young of domestic cattle. * Calf (leg), in humans (and other primates), the back portion of the lower leg Calf or calves may also refer to: Biology and animal byproducts * Veal, meat from calves * ...

is only visible from below.

Distribution

The Brazil-nut poison frog is endemic to the rainforest of central Brazil. It is known from several localities in the state of

; from Cachoeira Juruá,

Xingu River The Xingu River ( ; pt, Rio Xingu, ; Mẽbêngôkre: ''Byti'', ) is a river in north Brazil. It is a southeast tributary of the Amazon River and one of the largest clearwater rivers in the Amazon basin, accounting for about 5% of its water. ...

, the type locality; from Taperinha some to the north west; and from Flona Tapajos, Santarém. These locations are some distance apart and it is likely that this frog has a more widespread distribution than is known but has passed undetected in other parts of its range. It lives among the

leaf litter Plant litter (also leaf litter, tree litter, soil litter, litterfall or duff) is dead plant material (such as leaves, bark, needles, twigs, and cladodes) that have fallen to the ground. This detritus or dead organic material and its constituent ...

on the forest floor and sometimes climbs into low vegetation.

Biology

The Brazil-nut poison frog is diurnal and feeds on

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22 ...

termite Termites are small insects that live in colonies and have distinct castes (eusocial) and feed on wood or other dead plant matter. Termites comprise the infraorder Isoptera, or alternatively the epifamily Termitoidae, within the order Blattode ...

s and other small

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

s. The eggs are laid on the ground where they are guarded by the male. When they hatch, it carries the tadpoles to temporary pools such as water holes in trees and stumps, and water-filled empty nut cases on the forest floor. Here the tadpoles develop rapidly, devouring

mosquito Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin ''culex'' meaning " gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish for "li ...

larvae, smaller tadpoles, and other creatures that share these ephemeral pools, as well as suitably-sized plant material. This frog may become

sexually mature Sexual maturity is the capability of an organism to reproduce. In humans it might be considered synonymous with adulthood, but here puberty is the name for the process of biological sexual maturation, while adulthood is based on cultural definitio ...

in five to seven months.

Status

The Brazil-nut poison frog is common within its range and the population trend seems stable, although data on its conservation status is somehow insufficient. As a result, the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

lists its conservation status as being of "

least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

". The main threats it faces are

logging Logging is the process of cutting, processing, and moving trees to a location for transport. It may include skidding, on-site processing, and loading of trees or logs onto trucks or skeleton cars. Logging is the beginning of a supply chain ...

habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

wildfire A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire ...

and collection of animals to be sold as pets on an international market. There are some conservation areas within its range.

References

External links

{{Taxonbar, from=Q137827 Adelphobates Endemic fauna of Brazil Amphibians of Brazil Amphibians described in 1990 Taxonomy articles created by Polbot