Aplastodiscus leucopygius is a green tree frog that belongs to the A. albosignatus species group (Faivovich et al. 2005), in the Aplastodiscus (Hyla) albosignata complex (Cruz and Peixoto 1985). It is a medium sized frog for the group (35-45 mm SVL). Snout rounded in profile. Tympanum large, diameter about 2/3 to ¾ of the eye diameter, moderate tympanic fold; single vocal sac. Finger discs large. Dorsum smooth; diffuse glands along the entire flank. Venter granular. A white outlined transverse ridge above the vent composes the cloacal ornamentation. Prominent ovate inner metatarsal tubercle; heel with a fold and well-developed white calcar (Heyer et al. 1990).
Coloration: Dorsum bright green with small white spots. Belly creamy yellow with bits of white pigment flecks. Tarsal and supra-vent folds white highlighted, with dots spread laterally. Posterior surface of thigh unpigmented. Iris gold centrally and red or orange peripherally. Bones green (Heyer et al. 1990).
The tadpole has a mean total length of 52.4 mm at Gosner stage 28. Body elliptical in dorsal view, gray or light brown. Eyes dorsal. Snout rounded; nares kidney-like, closer to the eye than to the snout. Oral apparatus ventral. Marginal papillae in a single row; submarginal papillae present. LTRF 2(2)/4(1). Lower jaw V-shaped. Spiracle sinistral, directed upward, with the end point white. Vent tube dextral. Tail 69% of the total length, being the highest point at the first third, with rounded tip. Moderate tail musculature, with dark transverse bars. Fins reddish; ventral fin lower than the dorsal (Gomes and Peixoto 2002).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Brazil
Aplastodiscus leucopygius is found in the Atlantic Rainforest of Brazil, in the states of Rio de Janeiro, southern Minas Gerais, and eastern São Paulo. It lives near streams or temporary ponds associated with woodlands in the coastal mountains of southeastern Brazil, from 800 m up to 1,600 m a.s.l.
Life History, Abundance, Activity, and Special Behaviors
Males of this species call at night from high branches and leaves of trees (above 2 m), near permanent forest streams and rivulets, and less commonly at the forest edge (Heyer et al. 1990; Haddad and Sawaya 2000; Ribeiro et al. 2005). Each chorus can be composed of 4 or 5 calling males (Heyer et al. 1990). Males give three different vocalization types: advertisement calls, courtship calls, and multi-note (aggressive) calls. The advertisement call is the most common vocalization (Haddad and Sawaya 2000), which sounds like a horn (vocalizations can be heard on Haddad et al. 2005). Calling males use only one pond per reproductive period (Haddad and Sawaya 2000).
A. leucopygius is acoustically active throughout the year, but with a peak in activity during the rainy season, between October and March (Feio 1990; Haddad and Sawaya 2000). Gravid females and effective reproduction, however, were observed only from December to February in the Serra do Japi (Haddad and Sawaya 2000). An elaborate courtship takes place with a sequence of stereotypical mutual touches between the male and female, and the male eventually guides the female to the concealed subterranean nest (Haddad and Sawaya 2000). The female apparently inspects the nest before accepting the male (Haddad and Sawaya 2000), as is the case for another hylid species, Hypsiboas faber (Martins and Haddad 1988). A. leucopygius lays unpigmented eggs in a floating layer in these subterranean constructed nests, where the larvae also spend their early lives after hatching (Haddad and Sawaya 2000). Nests are made in muddy soil or banks near ponds and rivulets (Haddad and Sawaya 2000). Flooding washes the exotrophic tadpoles out of the nests, after which they occupy temporary ponds or streams (Haddad and Sawaya 2000; reproductive mode 5 of Haddad and Prado 2005). Tadpoles can inhabit streams varying in depth from 0.5 to 1 m, with the bottom composed of silt and litter.
A detailed description and discussion of the elaborate courtship behaviour can be found in Haddad and Sawaya (2000), including a description of the three types of vocalization, sexual selection, and the egg clutches, along with a discussion on the evolution of these behaviours and oviposition site.
Trends and Threats
Its range is within protected areas, like the Parque Estadual Nova Baden, at Lambari-MG, RPPN Ovidio Pires, at Bom Jardim-MG, Parque Estadual do Ibitipoca, at Lima Duarte-MG, Serra do Japi, at Jundiaí-SP, Parque Municipal do Itapetinga, at Atibaia-SP, Estação Biológica de Boracéia, at Salesópolis-SP, Parque Água Funda, at São Paulo, APA Federal da Bacia do Rio Paraíba do Sul, at Arujá-SP, Parque Nacional da Serra dos Órgãos, at Teresópolis-RJ, and Parque Nacional de Itatiaia, at Itatiaia-RJ (Cruz and Peixoto, 1985; Feio, 1990; Heyer et al., 1990; Haddad and Sawaya, 2000). A. leucopygius was apparently not affected by factors producing a drastic drop in abundance of several other anuran species in the Estação Biológica da Boracéia in 1979, as reported by Heyer et al. (1988).
Possible reasons for amphibian decline
General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Drainage of habitat
The epithet of this species (leucopygius) is related to the white parts of the cloaca and the calcaneous appendix.
This species was featured in News of the Week May 9, 2022:
Habitat fragmentation and infectious diseases are two of the biggest global threats to amphibians, but how do these two threats interact? Besides leading to stress and local extirpations in vulnerable wildlife populations, habitat fragmentation can reduce genetic diversity, which in turn may increase susceptibility to disease. Belasen et al. (2022) evaluated relationships between habitat fragmentation, genetic diversity, and disease susceptibility in six frog species endemic to Brazil’s Atlantic Forest, an amphibian diversity hotspot. They specifically tested whether habitat fragmentation reduces diversity in a genetic region related to immune function (MHC IIB), which is associated with amphibian susceptibility to the pathogen Batrachochytrium dendrobatidis (Bd). They found that habitat fragmentation was associated with genetic erosion at MHC IIB across species, and individuals that were MHC IIB heterozygotes (“hybrids”) experienced reduced Bd infection risk. The most severe genetic erosion at MHC IIB occurred in forest specialist frogs including Aplastodiscus leucopygius. Forest specialist frogs also exhibited increased Bd infections (higher prevalence and loads) in fragmented habitats. Overall their results showed that habitat fragmentation impacts MHC IIB diversity and potential disease susceptibility in frogs, with the greatest impacts in sensitive forest specialists. (Written by Anat M Belasen )
Cruz, C. A. G. and Peixoto, O. L. (1984). ''Espécies verdes de Hyla do complexo ''albosignata'' (Amphibia, Anura, Hylidae).'' Arquivos da Universidade Federal Rural do Rio de Janeiro, 7, 31-47.
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]
Feio, R. N. (1990). Aspectos ecológicos dos anfibios registrados no Parque Estadual do Ibitipoca, MG. (Amphibia, Anura). Master's Thesis, UFRJ-MN, Rio de Janeiro.
Gomes, M. R. and Peixoto, O. L. (2002). ''O girino de Hyla leucopygia Cruz and Peixoto, 1984 (Amphibia, Anura, Hylidae).'' Boletim do Museu de Biologia Mello Leitão (N. Sér.), 13(3), 17-25.
Haddad, C. F. B. and Sawaya, R. J. (2000). ''Reproductive modes of Atlantic Forest hylid frogs: a general overview and the description of a new mode.'' Biotropica, 32(3), 862–871.
Haddad, C. F. B., Giovanelli, J. G. R., Giasson, L. O. M., and Toledo, L. F. (2005). Guia sonoro dos anfíbios anuros da Mata Atlântica (Sound guide of the Atlantic rain forest anurans). Audio CD. NovoDisc Mídia Digital da Amazônia, Manaus.
Haddad, C. F. B., and Prado, C. P. A. (2005). ''Reproductive modes in frogs and their unexpected diversity in the Atlantic Forest of Brazil.'' BioScience, 55, 207-217.
Haddad, C. F. B., and Sazima, I. (1992). ''Anfíbios anuros da Serra do Japi.'' História Natural da Serra do Japi: Ecologia e Preservação de uma Área Florestal no Sudeste do Brasil. P. C. Morellato, eds., Unicamp, Campinas.
Heyer, W. R., Rand, A. S., Cruz, C. A. G., Peixoto, O. L., and Nelson, C. E. (1990). ''Frogs of Boracéia.'' Arquivos de Zoologia Sao Paulo, 31, 231-410.
Heyer, W. R., Rand, A. S., da Cruz, C. A. G., and Peixoto, O. L. (1988). ''Decimations, extinctions, and colonizations of frog populations in southeast Brazil and their evolutionary implications.'' Biotropica, 20(3), 230-235.
Martins, M., and Haddad, C. F. B. (1988). ''Vocalizations and reproductive behavior in the Smith frog, Hyla faber Wied (Amphibia: Hylidae).'' Amphibia-Reptilia, 9, 49-60.
Ribeiro, R. S., Egito, G. T. B. T., and Haddad, C. F. B. (2005). ''Chave de identificação: anfíbios anuros da vertente de Jundiaí da Serra do Japi, Estado de São Paulo.'' Biota Neotropica, 5(2), 235-247.
Zina, J., Ennser, J., Pinheiro, S. C. P., Haddad, C. F. B., and Toledo, L. F. (2007). ''Taxocenose de anuros de uma mata semidecídua do interior do Estado de São Paulo e comparações com outras taxocenoses do Estado, sudeste do Brasil.'' Biota Neotropica, 7, 1-9.
Originally submitted by: Diogo B. Provete (first posted 2009-01-10)
Edited by: Kellie Whittaker (2022-05-08)
Species Account Citation: AmphibiaWeb 2022 Aplastodiscus leucopygius: Guinle Treefrog <https://amphibiaweb.org/species/848> University of California, Berkeley, CA, USA. Accessed Apr 1, 2023.
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Citation: AmphibiaWeb. 2023. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 1 Apr 2023.
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