The species epithet, "arboreus" is of Latin origin and translates to “relating to trees”. The name was given because of the generally arboreal tendency of the species (Myers et al. 1984).

Description
Diagnosis: Oophaga arborea can be distinguished from other species of Oophaga by their spot pattern, call, and dentition. Although a few other Oophaga species exhibit similar spotting, O. arborea differs in the yellow color of their spots. These frogs exhibit raised spots, which do not occur in any other dendrobatid. The call, although similar, differs slightly from that of other Oophaga in its frequency, speed of note repetition, and the duration of single notes. Lastly, O. arborea lacks maxillary teeth, differentiating the species from its most similar looking relative, Ameerega maculata, by (Myers et al. 1984).

Description: Adults are small to medium sized, 20-22 mm in snout to vent length. Spots are normally smaller than the eye and are relatively round in shape. Spots may vary in size and arrangement, and some individuals’ spots are raised rather than flat. O. arborea lack both hand webbing and teeth. The iris of the eye is brown in color. Adult males have vocal slits on both sides and a moderately distensible vocal sac. When collapsed, the vocal sacs tend to form a pair of parallel folds on base of neck. The skin of the throat and chest is slightly wrinkled or granular, but the skin of the undersides of the belly and thighs are coarsely rugose. Hands are large, averaging about 30% of the snout vent length. The finger discs are expanded on all fingers except the first finger. The third finger disk is about 1.6-2.0 mm wider than neighboring fingers. The second finger is always longer than the first and when appressed, the first finger is approximately 3/4 the length of the second. The undersides of the fingers have tubercles that are low with rounded surfaces (Myers et al. 1984). The hindlegs are exceptionally short, unable to reach the eye. The inner and outer tubercles of the toes are the same size, but the outer one is more prominent (Myers et al. 1984).

Coloration: O. arborea has a uniform base color of either brown or black skin with bright yellow spotting dorsally and ventrally

Variation: O. arborea varies in base skin color from uniform brown to black as well as in the location and size of the spots (Myers et al. 1984).

Most juveniles are similar to adults in coloration and pattern. However, juveniles vary in the intensity of spots and may have a greenish tinge to the base color (Myers et al. 1984).

Tadpole Morphology: Tadpoles have a spiracle sinistral, and medial anus. Preserved specimens are uniformly grayish brown and have a light brown tail covered in white flecks. They have keratinized mouth-parts present (Myers et al. 1984).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Panama

View distribution map in BerkeleyMapper.

Endemic to the Atlantic lowlands and adjacent mountains of western Panama, the species occurs at a wide range of elevations from sea level to at least 1,120 m above sea level (Myers et al. 1984). The habitat of the arboreal species is a cooler cloud forest that frequently experiences rain and fog. The forest is very dense with trees, often covered in moist moss, and the forest floor is generally covered in plants, such as ferns. O. arborea are usually found in the sub-canopy heights of the forest, usually occupying the bromeliad plants, however this range may be larger depending on how high this specific species of vegetation grows on the tree (Myers et al. 1984).

Life History, Abundance, Activity, and Special Behaviors
Males utilize a call and sit on a bromeliad leaf to attract females. To signal her responsiveness, the female will drum her back legs and touch the male’s snout. After a complex set of chasing and body movements, the female and male assume a “vent to vent” position and the female lays about four to eight eggs on the leaves of bromeliads. The male then fertilizes them (Myers et al. 1984).

Parental care has been observed. The female will stay with the eggs for about half an hour after fertilization. When she leaves, the male will sit on top of the clutch. When the eggs hatch, tadpoles are carried into the water of bromeliads (Myers et al, 1984). Tadpoles hatched in captivity appeared to obtain all nutrients from their own yolk preserves (Myers et al. 1984).

Cannibalism has been observed. A female Polkadot Poison Frog was observed eating eggs off a bromeliad leaf near the water.

Trends and Threats
Logging and urban settlement has caused a high percentage of habitat loss, reducing the already small range of O. arborea. The species is also at risk for contracting chytridiomycosis (Solís et al, 2010). To date, O. arborea has been documented in two protected parks, Parque Internacional La Amistad and Bosque Protector Palo Seco (Solís et al. 2010).

Relation to Humans
O. arborea is highly toxic, containing many alkaloids that cause breathing difficulty, locomotor problems, and eventual death (Myers et al. 1984).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Urbanization
Habitat fragmentation
Disease

Comments
Species Authority: The first specimen was collected by Victor Martinez in 1981 (Myers et al, 1984).

Phylogeny: The species is believed to be a part of the histrionicus or pumilio species groups due to the morphology of tadpoles and the male’s call. The similar calls of all the species of histrionics serves as a distinct trait, forming a monophyletic unit. (Myers et al. 1984).

Taxonomy/Synonymy: The species was first described as Dendrobates arboreus by Myers et al. (1984), but was placed in the genus Oophaga in 1994 (Bauer 1994).

References

Bauer, Lucas (1994). ''New names in the family Dendrobatidae (Anura, Amphibia).'' RIPA, Fall, 1-6.

Brown J.L., Twomey E., Amézquita A., De Souza M.B., Caldwell J.P., Lötters S., Von May R., Melo-Sampaio P.R., Mejía-Vargas D., Perez-Peña P., Pepper M., Poelman E.H., Sanchez-Rodriguez M., and Summers K. (2011). "A taxonomic revision of the Neotropical poison frog genus Ranitomeya (Amphibia: Dendrobatidae)." Zootaxa, 3083, 1-120. [link]

Myers, C. W., Daly, J. W., and Martinez, V. (1984). ''An arboreal poison frog (Dendrobates) from western Panama.'' American Museum Novitates, 2783, 1-20.

Solís, F., Ibáñez, R., Jaramillo, C., and Fuenmayor, Q. (2009). Oophaga arborea. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4. www.iucnredlist.org. Downloaded on 29 April 2011.

Species Account Citation: AmphibiaWeb 2024 Oophaga arborea: Polkadot Poison Frog <https://amphibiaweb.org/species/1624> University of California, Berkeley, CA, USA. Accessed Dec 23, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 23 Dec 2024.

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