A large treefrog. Males 101-128 mm, females 91-123 mm. The dorsum is brown in males and orange-brown in females. The ventral surface is cream to whitish in both sexes. Transverse darker bars occur on the sides of the body and legs. The membrane between the fingers is complete to the start of the terminal segment of the finger. The iris is orange brown with a diamond pupil.
Diagnosis: Osteocephalus taurinus is similar in size and color, but its iris is golden with radiating lines. Hyla lanciformis is easily distinguished by the white stripe along its mouth, and the white terminal discs on the first, second and third toes of the fore feet. Young H. boans can be distinguished from H. geographica because H. geographica has a blue membrane over the upper part of the eye, and an orange abdomen.
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Panama, Peru, Suriname, Trinidad and Tobago, Venezuela
Widely distributed through the Amazon Basin of Brazil, Bolivia, Peru, Ecuador, and Colombia including the upper Orinoco and Magdalena Basins, and Guianas. It is also found in the Pacific lowlands of Colombia and adjacent Ecuador to eastern Panama and Trinidad.
This species is common near streams on the edge of the Reserva Florestal Adolpho Ducke in Brazil, and around Acará, Bolivia, Ipiranga and Tinga streams.
Life History, Abundance, Activity, and Special Behaviors
The species is arboreal and nocturnal, and reproduces mainly in the dry season between July and December. Clutches of 1300-3000 eggs are deposited as a gelatinous film on the water surface in nest basins constructed by the male, or in natural depressions formed in leaf litter or roots. The nest basins often have permanent aquatic connections to streams.
Males use exposed bones on their thumbs to fight in defense of egg-laying sites.
The tadpoles are light brown to whitish, live on sand or litter banks in streams and are unpalatable to fish.
This species was featured in news of the week 14 November 2022:
The pupil is the aperture of the eye, and its size and shape can have important consequences for vision. Most vertebrate pupils are large and round when dilated but can vary in shape and orientation when constricted. Amphibians exhibit extraordinary diversity in the shapes of their constricted pupils, but until recently the evolution of this trait had not been explored. Thomas et al. (2022) surveyed pupil shape from photographs in 1,294 species of frogs, salamanders, and caecilians. They found that pupil shape has high evolutionary lability, particularly among frogs, and is correlated with aspects of ecology. Species living aquatic and fossorial lifestyles typically have non-elongated pupils, while those in other habitats are more likely to have horizontally or vertically elongated pupils. Eye size also was correlated with pupil elongation, with larger eyes more likely to have elongated pupils. Finally, pupil shape varied across life stages: frog and salamander larvae typically have circular pupils that can remain circular or change to elongated pupil shapes after metamorphosis. AmphibiaWeb photos played a crucial role in this study, as well as another recent study on amphibian pupils from Cervino et al. (2021). (Written by Rayna Bell)
Originally submitted by: Albertina P. Lima, William E. Magnusson, Marcelo Menin, Luciana K. Erdtmann, Domingos J. Rodrigues, Claudia Keller, Walter Hödl (first posted 2007-11-21)
Edited by: Tate Tunstall, Michelle S. Koo (2022-11-13)
Species Account Citation: AmphibiaWeb 2022 Boana boans: Giant Gladiator Treefrog <https://amphibiaweb.org/species/739> University of California, Berkeley, CA, USA. Accessed Sep 28, 2023.
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Citation: AmphibiaWeb. 2023. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 28 Sep 2023.
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