Perez's Snouted Frog
© 2011 Tiffany Kosch (1 of 5)
Edalorhina perezi is a toad-like South American frog with an appearance similar to that of a dead leaf. Snout-vent length ranges from 24 - 37 mm, with females being larger than the males (Deichmann et al. 2008). The snout is rounded, often with a cone shaped tubercle at the tip. Its tympanum is oval, with a length about the same as the eye. Above the eye sit several dermal protrusions (“horns”), which look similar to eyelashes. A dermal fold runs from behind the eye to the hind leg insertions, and gives E. perezi a flat, leaf-like appearance when viewed form above (Cope 1874). Vomerine teeth are either poorly developed or absent. Toes are slightly webbed (Dunn 1949).
Tadpoles hatch at stage 25 with a body length of around 4.1 mm and a total length of around 10.5 mm. The body is robust and wider than it is deep. Snout is rounded, eyes are located dorsolaterally. The mouth is anteroventrally oriented. The caudal fins are equal in depth to the tail musculature and each other. Tail tip is rounded (Schlüter 1990). Two upper and two lower rows of denticles are present. The tadpoles do not have external gills or adhesive organs. Tadpoles at stage 41 have a body length of 10.1 - 10.2 mm and a total length of 27.1 - 27.9 mm (Duellman and Morales 1990).
Adult E. perezi can be distinguished from its sister taxon E. nasuta by the shape and characters of the head. E. perezi has a short, rounded snout and very prominent tubercles on the upper eyelid, while E. nasuta has a long, pointed, fleshy snout and less pronounced eyelid tubercles (Duellman and Morales 1990).
The dorsum and dorsal surfaces of the limbs may be blotched or striped brown, while the venter is white with black bands and spots. The sides of the body are black. Bright yellow coloration may be seen on the undersides and insertions of the limbs (Cope 1874).
Dorsal skin texture and ventral color pattern vary geographically. The dorsum may be smooth, have 4-5 tubercles, have many tubercles, or have paired dermal ridges running down the back. The venter can range from mostly white with black present laterally to all black other than a white throat with black flecks (Duellman and Morales 1990). Vomerine teeth and an interocular dermal ridge may also be present or absent depending on location. Development of a wart on the snout also varies between individuals (Dunn 1949).
Edalorhina perezi tadpoles are light brown with darker brown mottling on their top and sides (Schlüter 1990).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Brazil, Colombia, Ecuador, Peru
Edalorhina perezi is distributed throughout the Amazonian lowlands of Peru, Ecuador, southern Colombia, western Brazil, and possibly Bolivia. It is found between 100 and 1100 meters above sea level (Angulo et al. 2004).
Edalorhina perezi is diurnal and inhabits leaf litter in the lowland and premontane forests east of the Andes. The species can also be found in secondary or disturbed forest habitats (Angulo et al. 2004).
Life History, Abundance, Activity, and Special Behaviors
Edalorhina perezi can be found in shaded leaf litter during the day, and is most active following rains (Duellman and Morales 1990).
During the breeding season, males are solitary vocalists (no breeding aggregations), calling from the forest floor, well distanced from one another. The call consists of three to five low pitched, short whistles that are frequency modulated with a dominant frequency around 2700 Hz. Harmonics are present at 5400 and 8100 Hz. The call is repeated four or five times, with 0.13 - 0.20 seconds between calls. Call groups are spaced several minutes apart (Duellman and Morales 1990).
Amplexus in E. perezi is axillary, and may last for up to 6 days. The female secretes the material that will make up the nest, then the male “beats” it into foam. Nest construction takes 30 minutes to 2 hours. Multiple nests may be constructed in one night with each being between 50 - 75 mm in diameter. Up to thirty to forty small, unpigmented eggs (around 2.5mm diameter) are laid in each nest (Schlüter 1990). Tadpoles develop in the nest for 4 - 5 days, and then exit the nest at stage 25 with a body length of around 4.1 mm and a total length of around 10.5 mm (Duellman and Morales 1990).
Trends and Threats
Edalorhina perezi has a wide range, a large, stable population, and is tolerant to modified or disturbed habitats. The species also occurs in many protected areas throughout its range. Local populations may be threatened by habitat loss due to logging or agriculture, but the species as a whole is not threatened (Angulo et al. 2004).
Possible reasons for amphibian decline
General habitat alteration and loss
The species authority for E. perezi is Don Marcos Jiménez de la Espada, 1871.
Edalorhina perezi is synonymous with Bubonias plicifrons (Cope, 1874) and E. buckleyi (Boulenger, 1882). Edalorhina perezi was distinguished based on characters such as wart organization and vomerine teeth, which are now considered to be variation within a single species (Dunn 1949).
Edalorhina perezi is the sister taxon to E. nasuta, the only other member of Edalorhina. The closest relatives of the genus,Edalorhina, are the genera Physalaemus and Pleurodema (Lourenço et al. 2000).
Edalorhina perezi has a diploid number of 2n=22 (Lourenço et al. 2000).
Angulo, A., Azevedo-Ramos, C., Coloma, L. A., Santiago, R. (2004). Edalorhina perezi. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. www.iucnredlist.org. Downloaded on 26 February 2013.
Cope, E. D. (1874). ''On Some Batrachia and Nematognathi Brought from the Upper Amazon by Prof. Orton.'' Proceedings of the Academy of Natural Sciences of Philadelphia, 26(2), 120-137.
Deichmann, J. L., Duellman, W. E., and Williamson, G. B. (2008). ''Predicting Biomass from Snout–Vent Length in New World Frogs.'' Journal of Herpetology, 42(2), 238-245.
Duellman, W. E., and Morales, V. R. (1990). ''Variation, distribution, and life history of Edalorhina perezi (Amphibia, Anura, Leptodactylidae).'' Studies on Neotropical Fauna and Environment, 25(1), 19-30.
Dunn, E. R. (1949). ''Notes on the South American Frog Genus Edalorhina.'' American Museum Novitates, (1416).
Lourenço, L. B., Cardoso, A. J., Recco-Pimentel, S. M. (2000). ''Cytogenetics of Edalorhina perezi (Anura, Leptodactylidae).'' Cytologia, 65, 359-363.
Schlüter, A. (1990). ''Reproduction and Tadpole of Edalorhina perezi (Amphibia, Leptodactylidae).'' Studies on Neotropical Fauna and Environment, 25(1), 49-56.
Written by John Cavagnaro (john.cavagnaro AT berkeley.edu), Museum of Vertebrate Zoology, UC Berkeley
First submitted 2013-02-26
Edited by Ann T. Chang & Rudolf von May (2013-03-29)
Species Account Citation: AmphibiaWeb 2013 Edalorhina perezi: Perez's Snouted Frog <http://amphibiaweb.org/species/3307> University of California, Berkeley, CA, USA. Accessed Nov 20, 2018.
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Citation: AmphibiaWeb. 2018. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 20 Nov 2018.
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