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Description
This species can be diagnosed by the following combination of characters: body size (females 34-37 mm SVL, males 24-29 mm SVL); smooth dorsal skin; axillary membrane present; fingers one-half webbed; toes two-thirds webbed; dorsum mottled dark and light brown; lighter markings of creamy white to golden yellow with irregular edges: broad light mark on snout, diagonal light mark running from eyelid to mid-flank, diagonal mark on shank; orange coloration on hands, feet, concealed surfaces of limbs, ventral surfaces of limbs; coppery bronze iris; males with yellow vocal sac and lacking nuptial pads; females with white throat (Rodríguez and Duellman 1994).

Similar species: D. sarayacuensis can be distinguished from D. leucophyllatus by coloration (mottled dark and light brown dorsum with white to golden yellow markings for D. sarayacuensis, vs. creamy tan dorsum with a dark brown hourglass marking for D. leucophyllatus. D. sarayacuensis can be distinguished from D. triangulum by coloration (orange hands, feet, and concealed surfaces of limbs in D. sarayacuensis, vs. distinctly red webbing and red concealed surfaces of limbs in D. triangulum) (Rodríguez and Duellman 1994).

Tadpoles reach a maximum total length of 22.5 mm, with 30% of that being body and 70% the tail. The larval body is violin-shaped when viewed from above, with a tail ending in a long filament. The snout is bluntly rounded when viewed from above. Eyes are large and are laterally directed. The oral disc is anterior and is bordered by a single row of papillae laterally and ventrally; denticles are absent. Jaw sheats are finely serrated and are robust. The dorsal tail fin does not extend onto the body and is slightly lower than the ventral tail fin. The larval body is reddish brown to gray, with a metallic gold venter and a black or gray tail with black markings (Rodríguez and Duellman 1994). For a drawing of the tadpole and a key to hylid tadpoles of the eastern lowlands of Colombia see Lynch and Mayorga (2011).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Bolivia, Brazil, Colombia, Ecuador, Peru, Venezuela

View distribution map in BerkeleyMapper.

D. sarayacuensis inhabits the upper Amazon Basin, in Ecuador (Shreve 1935; Duellman 1972; Duellman and Pyles 1983; Pearman 1997; Bustamante et al. 2005), Peru (Toft and Duellman 1979; Rodríguez and Duellman 1994; von May et al. 2008), Brazil (Heyer 1977; Aichinger 1987; Gascon and Pereira 1993; Galatti 1999; Bernarde et al. 2011), Colombia (Ruiz-Carranza et al. 1996; Lynch 2005), and northwestern Bolivia (de la Riva et al. 2000); this species has also been reported from Cerro Neblina in the far southern part of Amazonas state, Venezuela (McDiarmid and Paolillo 1988; Barrio-Amorós 1998). It is an arboreal species and can be found in understory vegetation in both primary and secondary rainforest, as well as at forest edges (La Marca et al. 2004). It occurs at elevations up to 1,700 m asl (Bustamante et al. 2005).

Life History, Abundance, Activity, and Special Behaviors
This species is nocturnal and arboreal (La Marca et al. 2004). It is found on low vegetation <1.5 m above ground (Toft and Duellman 1979). In life, this species has a distinctive herbal odor (Rodríguez and Duellman 1994). Breeding takes place at forest pools (Duellman and Pyles 1983), and occurs only during the six month rainy season (Aichinger 1987). Aichinger (1987) found this species at Panguana (Upper Amazon Basin, Brazil) in a large temporary forest pond (filled throughout the rainy season) along with 22 other species. Males call in choruses, with groups of 5-10 males (Aichinger 1987). Advertisement calls at Santa Cecilia, Ecuador were found to consist of a single note per call group with a single secondary note, at an average dominant frequency of 2.99 kHz (range 2.848-3.326 kHz) and an average pulse rate of 78 pulses/second (range 60-80); the note is repeated 26.8x per minute (range 22.2-33.3x), on average, and lasts 0.08 seconds (range 0.03-0.11 second) (Duellman and Pyles 1983). Rodríguez and Duellman (1994) reported that advertisement calls at Iquitos, Peru, consisted of a single primary note followed by one or two shorter notes.

Oviposition takes place during early morning, after rainfall, on the upper surfaces of leaves, moss-covered roots and tree trunks near or above the water (Hödl 1991; Rodríguez and Duellman). Hödl (1991) describes breeding behavior as follows: First, the male clasps the female and positions its cloaca directly above that of the female. Carrying the amplexed male, the female climbs to a vertical structure overhanging a water body. She deposits egg masses at regular intervals in an arching position. Between each bout of egg deposition, she climbs 1 to 3 cm, resulting in a long series of successfully laid egg masses. Eggs are highly adherent, making brushing and smoothing of the clutch unnecessary. The whole process lasts between 17 to 34 minutes. According to Hödl (1991), an average of 141 eggs are laid during 5 to 8 bouts; the range is 68-176 eggs per clutch (Rodríguez and Duellman). The egg jelly swells up by absorbing water from the humidity-saturated air and wet substrate. Larvae fall into the water ten to thirteen days after oviposition (Hödl 1991).

The tadpole of D. sarayacuensis undergoes oral development resembling that of Hyla chrysoscelis until stage 24, when the oropharyngeal membrane ruptures (see Thibaudeau and Altig 1988 for scanning electron micrographs). The tadpole lacks a typical oral disc and labial teeth (denticles). Although vestigial labial tooth ridges are present throughout tadpole ontogeny, teeth never appear. By stage 25, serrated, fully keratinized jaw sheaths are present, as well as two large, lateral papillae, with posteriomedial papillae becoming evident soon thereafter. Larvae of this species are thought to feed by tearing off suitable pieces of material from submerged substrates.

This species is susceptible to infection by the cosmocercid nematode Cosmocerca brasiliense (also known as C. brasiliensis; Dyer and Altig 1976, 1977).

Trends and Threats
It is most common in Peru and Ecuador (La Marca et al. 2004). It appears to be able to tolerate some habitat disturbance (La Marca et al. 2004). It is known to occur within many protected areas, some examples of which follow. Within Ecuador, its range overlaps with a number protected areas, including Parque Nacional Sumaco Napo-Galeras, Parque Nacional Yasuní, and Reserva Biológica Limoncocha (La Marca et al. 2004). Within Peru, it is found in Manu National Park (Rodriguez and Cadle 1990), as well as in protected areas (Cocha Cashu, Centro Sachavacayoc, Eco Amazonia, Explorer’s Inn, and Pakitza) in the Madre de Dios region (von May et al. 2008). In Brazil, it is found within the Reserva Extrativista Riozinho da Liberdade, Acre (Bernarde et al. 2011).

Relation to Humans
This species may be collected for the pet trade, although it is not clear whether specimens represent D. sarayacuensis or D. triangulum; Rowley et al. (2007) noted six individuals were imported into Hong Kong from Germany but did not distinguish between these species.

Comments
First described by Shreve (1935); the name sarayacuensis refers to the type locality of Sarayacu, province of Pastaza, Ecuador. Faivovich et al. (2005) placed D. sarayacuensis in the leucophyllatus group with D. bifurcus, D. ebraccatus, D. elegans, D. leucophyllatus, D. rossalleni, and D. triangulum, and the analysis of Wiens et al. (2010) also supports this grouping. Wiens and colleagues found that D. anceps did not cluster with this group, in contrast to the analysis of Faivovich et al. (2005).

Click here to download a .pdf of Hödl's (1991) paper describing the film.

References

Aichinger, M. (1987). ''Annual activity patterns of anurans in a seasonal neotropical environment.'' Oecologia, 71, 583-592.

Barrio-Amorós, C. L. (1998). ''Sistematica y biogeografía de los anfibios (Amphibia) de Venezuela.'' Acta Biologica Venezuelica, 18, 1-93.

Barrio-Amorós, C. L. (1998). ''Sistematica y biogeografía de los anfibios (Amphibia) de Venezuela/Systematics and biogeography of the amphibians (Amphibia) of Venezuela.'' Acta Biologica Venezuelica, 18, 1-93.

Bernarde, P. S., Machado, R. A., and Turci, L. C. B. (2011). ''Herpetofauna da área do Igarapé Esperança na Reserva Extrativista Riozinho da Liberdade, Acre - Brasil.'' Biota Neotropica, 11, 117-144.

Bustamante, M. R., Ron, S. R., and Coloma, L. A. (2005). ''Cambios en la diversidad en siete comunidades de anuros en los Andes de Ecuador.'' Biotropica, 37, 180-189.

Crump, M. L., and Kaplan, R. H. (1979). ''Clutch energy partitioning of tropical tree frogs (Hylidae).'' Copeia, 1979, 626-635.

De la Riva, I., Köhler, J., Lötters, S. and Reichle, S. (2000). ''Ten years of research on Bolivian amphibians: updated checklist, distribution, taxonomic problems, literature and iconography.'' Revista Espanola de Herpetologia, 14, 19-164.

Duellman, W. E. (1972). ''A new species of Hyla from Amazonian Ecuador.'' Copeia, 2, 265-271.

Duellman, W. E. and Pyles, R. A. (1983). ''Acoustic resource partitioning in anuran communities.'' Copeia, 3, 639-649.

Dyer, W. G., and Altig, R. (1976). ''Redescription of Cosmocerca brasiliensis Travassos 1925 (Nematoda: Cosmocercidae) from Ecuadorian frogs.'' The Journal of Parasitology, 62, 262-264.

Dyer, W. G., and Altig, R. (1977). ''Helminths of some Ecuadorian anurans.'' Herpetologica, 33, 293-296.

Faivovich, J., Haddad, C. F. B., Garcia, P. C. A., Frost, D. R., Campbell, J. A., Wheeler, W. C. (2005). ''Systematic review of the frog family Hylidae, with special reference to Hylinae: phylogenetic analysis and taxonomic revision.'' Bulletin of the American Museum of Natural History, (294), 1-240. [link]

Galatti, U. (1999). Avaliação ecológica rápida da Reserva Biológica Estadual Rio Ouro Preto, Guajará-Mirim, Rondônia. Inventário da herpetofauna da Res. Biol. rio Ouro Preto. Final Report. Programa das Nações Unidas para o Desenvolvimento / Plano Agropecuário e Florestal de Rondôdia (PNUD/PLANAFLORO), Rôndonia, Brazil.

Gascon, C. and Pereira, O. S. (1993). ''Preliminary checklist of the herpetofauna of the upper rio Urucu, Amazonas.'' Revista Brasileira de Zoologia, 10, 179-183.

Heyer, W. R. (1977). ''Taxonomic notes on frogs from the Madeira and Purus rivers, Brasil.'' Papeis Avulsos de Zoologia, 31, 141-162.

Hödl, W. (1991). ''Arboreal oviposition in the neotropical treefrogs Hyla brevifrons and Hyla sarayacuensis (Anura: Hylidae).'' Wiss. Film (Wien), 42, 53-62.

Lynch, J. D. (2005). ''Discovery of the richest frog fauna in the world—an exploration of the forests to the north of Leticia.'' Revista de la Academia Colombiana de Ciencias, 29, 581-588.

Lynch, J. D. and Mayorga, A. M. S. (2011). ''Clave ilustrada de los renacuajos en las tierras bajas al oriente de los Andes, con énfasis en Hylidae.'' Caldasia, 33, 235-270.

McDiarmid, R. W. and Paolillo, A. (1988). ''Herpetological collections: Cerro de la Neblina.'' Cerro de la Neblina: Resultados de la expedición 1983-1987. FUDECI, Caracas.

Pearman, P. B. (1997). ''Correlates of amphibian diversity in an altered landscape of Amazonian Ecuador.'' Conservation Biology, 11, 1211-1225.

Rodriguez, L. B., and Cadle, J. E. (1990). ''A preliminary overview of the herpetofauna of Coca Cashu, Manu National Park, Peru.'' Four Neotropical Rainforests. A. H. Gentry, eds., Yale University Press, New Haven, Connecticut.

Rodríguez, L. O., and Duellman, W. E. (1994). Guide to the Frogs of the Iquitos region, Amazonian Perú. The University of Kansas, Lawrence, Kansas.

Rowley, J. J. L., Chan, S. K. F., Tang, W. S., Speare, R., Skerratt, L. F., Alford, R. A., Cheung, K. S., Ho, C. Y., and Campbell, R. (2007). ''Survey for the amphibian chytrid Batrachochytrium dendrobatidis in Hong Kong in native amphibians and in the international amphibian trade.'' Diseases of Aquatic Organisms, 78, 87-95.

Ruiz-Carranza, P.M., Ardila-Robayo, M.C., and Lynch, J.D (1996). ''Lista actualizada de la fauna de Amphibia de Colombia.'' Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales, 20(77), 365-415.

Shreve, B. (1935). ''On a new teiid and amphibia from Panamá, Ecuador, and Paraguay.'' Occasional Papers of the Boston Society of Natural History, 8, 209-218.

Thibaudeau, D. G., and Altig, R. (1988). ''Sequence of ontogenetic development and atrophy of the oral apparatus of six anuran tadpoles.'' Journal of Morphology, 197, 63-69.

Toft, C. A., and Duellman, W. E. (1979). ''Anurans of the lower Río Llullapichis, Amazonian Perú: a preliminary analysis of community structure.'' Herpetologica, 35, 71-77.

Wiens, J. J., Kuczynski, C. A., Hua, X., and Moen, D. S. (2010). ''An expanded phylogeny of treefrogs (Hylidae) based on nuclear and mitochondrial sequence data.'' Molecular Phylogenetics and Evolution, 55, 871-882.

Species Account Citation: AmphibiaWeb 2012 Dendropsophus sarayacuensis: Sarayacu Treefrog <https://amphibiaweb.org/species/948> University of California, Berkeley, CA, USA. Accessed Nov 23, 2024.

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

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