The Rockstone poison dart frog (''Dendrobates nubeculosus'') is a poorly known species of dendrobatid

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

to Guyana. As it is known from only one specimen, very little information is currently available on ''D. nubeculosus''. It has been suggested to be one of the most poorly known species in the world.

Description

''D. nubeculosus'' is a small to medium-sized poison dart frog; larger than many of its contemporary '' Ranitomeya'' species, but smaller than the other members of the genus ''

Dendrobates ''Dendrobates'' is a genus of poison dart frogs native to Central and South America. It once contained numerous species, but most originally placed in this genus have been split off into other genera such as ''Adelphobates'', ''Ameerega'', ''Andi ...

''. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of seve ...

specimen measures 2.5 centimetres in length, and the species' size range is unknown. It is reasonably certain that, like other members of the genus ''Dendrobates'', ''D. nubeculosus'' females are larger than males, but even this is open to speculation. The holotype is primarily black or dark brown, with irregularly shaped blue splotches on the dorsum, and it is mottled blue and black laterally, with a solid black ventral surface. It is unclear whether, as with other ''Dendrobates'' species, ''D. nubeculosus'' is polymorphic. Nothing is known about ''D. nubeculosus social behaviour, reproductive habits, call, or toxicity. It is assumed that the breeding habits of ''Dendrobates nubeculosus'' are similar to that of its

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

, '' D. leucomelas''.

Habitat

''D. nubeculosus'' is only known from a single specimen collected by

ornithologist Ornithology is a branch of zoology that concerns the "methodological study and consequent knowledge of birds with all that relates to them." Several aspects of ornithology differ from related disciplines, due partly to the high visibility and th ...

s in the 1980s. No precise habitat data exist but the vegetation in the area of the

type locality Type locality may refer to: * Type locality (biology) * Type locality (geology) See also * Local (disambiguation) * Locality (disambiguation) {{disambiguation ...

, near

Rockstone Rockstone is a village on the right bank of the Essequibo River in the Upper Demerara-Berbice Region of Guyana, altitude 6 metres (22 feet). Rockstone is approximately 26 km west of Linden and is linked by road. The village demographics are mo ...

, a town on the

Essequibo River The Essequibo River (Spanish: ''Río Esequibo'' originally called by Alonso de Ojeda ''Río Dulce'') is the largest river in Guyana, and the largest river between the Orinoco and Amazon. Rising in the Acarai Mountains near the Brazil–Guyana b ...

lowland Upland and lowland are conditional descriptions of a plain based on elevation above sea level. In studies of the ecology of freshwater rivers, habitats are classified as upland or lowland. Definitions Upland and lowland are portions of p ...

jungle A jungle is land covered with dense forest and tangled vegetation, usually in tropical climates. Application of the term has varied greatly during the past recent century. Etymology The word ''jungle'' originates from the Sanskrit word ''ja� ...

References

{{Taxonbar, from=Q1348424 Dendrobates Endemic fauna of Guyana Amphibians of Guyana Poison dart frogs Amphibians described in 2004