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Order: Anura
Family: Microhylidae
The Microhylidae (the “narrow-mouthed frogs”) is one of the most recently evolved families of frogs and, with a total of over 400 species, are also the largest with the greatest number of genera (nearly 50). They are a very large and diverse family of frogs, widely distributed throughout the tropics. They include both burrowing / terrestrial (ground-dwelling) and arboreal (tree-dwelling) species. The narrow-mouthed frogs diverged from all other amphibians about 80 million years ago, which is around same time that beavers and mice shared a common ancestor.
The narrow-mouthed frogs comprise 10 subfamilies, and the Malagasy rainbow frog is a member of the Scaphiophryninae subfamily, which includes 8 species, all of which are present in the single genus Scaphiophryne, the “Madagascar narrow-mouthed frogs”. In Madagascar, the Microhylid family is represented by 10 genera that are found nowhere else on earth (they are “endemic”). Scaphiophryne is thought to have differentiated from the other genera about 70 million years ago in the Late Cretaceous. In terms of mammalian evolution, they are as dissimilar from all other amphibian species as pigs are from giraffes.
Many of the microhylid species, like the Malagasy rainbow frog, are stout-bodied burrowers capable of climbing. Whereas the majority of the climbing microhylids are arboreal (or tree-dwelling), the Malagasy rainbow frog is a rock climbing species, adapted to life in the canyons of Madagascar’s Isalo Massif. This species has highly prehensile fingers with pads at the tips which help them to climb, and their feet have horny wart-like structures which also facilitate climbing, as well as swift burrowing. Its tadpoles have evolved the ability to develop quickly in temporary rock pools so avoid getting washed away during heavy rains. With its red, green and black marking, this species is the most colourful and striking member of its genus, which accounts for it popularity in the pet trade.
The narrow-mouthed frogs comprise 10 subfamilies, and the Malagasy rainbow frog is a member of the Scaphiophryninae subfamily, which includes 8 species, all of which are present in the single genus Scaphiophryne, the “Madagascar narrow-mouthed frogs”. In Madagascar, the Microhylid family is represented by 10 genera that are found nowhere else on earth (they are “endemic”). Scaphiophryne is thought to have differentiated from the other genera about 70 million years ago in the Late Cretaceous. In terms of mammalian evolution, they are as dissimilar from all other amphibian species as pigs are from giraffes.
Many of the microhylid species, like the Malagasy rainbow frog, are stout-bodied burrowers capable of climbing. Whereas the majority of the climbing microhylids are arboreal (or tree-dwelling), the Malagasy rainbow frog is a rock climbing species, adapted to life in the canyons of Madagascar’s Isalo Massif. This species has highly prehensile fingers with pads at the tips which help them to climb, and their feet have horny wart-like structures which also facilitate climbing, as well as swift burrowing. Its tadpoles have evolved the ability to develop quickly in temporary rock pools so avoid getting washed away during heavy rains. With its red, green and black marking, this species is the most colourful and striking member of its genus, which accounts for it popularity in the pet trade.
As their name would suggest, the Malagasy rainbow frog is one of the most highly decorated of the Madagascan frogs. They are medium in size and conspicuously coloured, with a distinctive white, red, green and black pattern on the back. They have a roundish body and prominent brown eyes. The skin of the back is very smooth, whilst the skin of the grey belly is slightly rough. They have a shortened snout and a small mouth. At an adult length of 30 to 40 mm, the females are slightly bigger than the males, which generally grow to 20 to 30 mm in length and are paler in colour than the females. The tadpoles are quite big and blackish.
Adapted for both burrowing and climbing lifestyles, the Malagasy rainbow frog has large shovel-shaped horny tubercles (wart-like swellings) on the underside of the hind feet to help with burrowing, and wide, adhesive discs on the fore feet for clinging to vertical canyon walls. The fingers have “claw-like” structures, which are actually a highly prehensile tip of each digit with horny skin that improves grip during climbing. Only the hind feet are webbed and the legs are relatively short, although this species is actually quite a poor swimmer.
Adapted for both burrowing and climbing lifestyles, the Malagasy rainbow frog has large shovel-shaped horny tubercles (wart-like swellings) on the underside of the hind feet to help with burrowing, and wide, adhesive discs on the fore feet for clinging to vertical canyon walls. The fingers have “claw-like” structures, which are actually a highly prehensile tip of each digit with horny skin that improves grip during climbing. Only the hind feet are webbed and the legs are relatively short, although this species is actually quite a poor swimmer.
The Malagasy rainbow frog leads a very secretive lifestyle. Seasonal climatic variations reduce this species’ main period of activity to the rainy season, and so this species can only be found at certain times of the year, especially between November and April after heavy rainfall. When conditions are wet, Malagasy rainbow frogs may be seen moving around on the ground. At other times these frogs burrow into the ground, or hide beneath rocks and in deep crevices.
During the rainy season (around October to February) the Isalo canyons become temporary fast running streams. After the rainfall the water remains in small pools within the rocks, creating the pools in which the Malagasy rainbow frog breeds. This species is adapted both for burrowing and climbing, which allows it to inhabit a varied environment of open, rocky areas of dry forest and the limestone canyons of the Isalo Massif. It has been observed jumping on to vertical canyon walls and climbing several meters from the ground. However, it is predominantly known for its underground lifestyle, and is thought to climb only to escape drowning in flash floods by finding refuge in small holes present higher up the canyon walls. These occur in the rock in areas where chalks have been lost from Isalo’s limestone karstic matrix. Despite its webbed hind feet, this species is not a strong swimmer. When burrowing, this species digs into the sands or soft substrate available in its natural habitat using specially adapted hind limbs.
Malagasy rainbow frogs live for 4-7 years and this species becomes sexually mature after 1-2 years. The breeding season runs from December to January, and 1000s of eggs can be produced by each female in a single spawning. Eggs are laid in temporary rock pools and the tadpoles are thought to develop relatively quickly (in 1-2 months) to avoid being washed away by sudden heavy rains. Tadpoles feed by filtering detritus from sand in the small rock pools where they live. During the night, they become very active and occupy the whole water column. Adult Malagasy rainbow frogs consume insects and other small invertebrates.
In the Vallée des Singes, the landscape is a type of oasis which was shaped into canyons along streams and rivers. Here, a special microclimate has developed which allows the frogs to survive in an otherwise hot and dry area. The Malagasy rainbow frog inhabits open, rocky areas of dry forest, as well as hiding amongst stone crevices in canyons. It breeds in shallow, temporary pools within the canyons, although sometimes could be found in open areas. This species occupies an area of around 25 by 80 km, or up to 2,000 km sq.. This species is only found in the vicinity of water.
The Malagasy rainbow frog is known only from the dry, hilly regions of the Vallée des Singes, Isalo (in the Province of Fianarantsoa), southwestern Madagascar. This species is restricted to a few areas within the Isalo Massif at altitudes of 700-1,000 metres above sea level. It has been found within the Isalo National Park boundary, and also further to the north at Ilakaka. Intensive surveys close to these areas have not recorded any further populations.
The Malagasy rainbow frog appears to be locally abundant in the humid canyons.
This species is thought to be in decline by the IUCN Red List of Threatened Species
The Malagasy rainbow frog is listed as Critically Endangered because its extent of occurrence is less than 100 km sq., all individuals are in a single location, and there is continuing decline in the extent and quality of its habitat around Isalo, and it is possibly subject to over-collecting for the pet trade leading to a decline in the number of mature individuals. Scaphiophryne gottlebei is currently listed by CITES under appendix II (Convention on International Trade in Endangered Species of Wild Fauna and Flora), although the University of Tana in Madagascar has recommended that the annual export quota for this species be restricted to fewer than 1000 individuals per year.
Over-collection for the international pet trade could be a significant threat to this restricted-range species. Thousands of Malagasy rainbow frogs are captured for the pet trade each year and, despite being Critically Endangered, it is still commonly recorded in international trade. However, it is locally abundant and has a high reproductive rate, which may allow for fast recovery from minor reductions in population numbers. This species’ habitat is also at risk from fire, wood extraction, overgrazing by livestock, and recent sapphire mining activities in areas adjacent to the species' known range. Disturbance by tourists within the range of this species are reported to have increased, although the extent of the impact is unclear.
This species occurs in the Isalo National Park which affords it a certain amount of protection from habitat loss. The Malagasy rainbow frog is currently listed by CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) under appendix II, although the University of Tana in Madagascar has recommended that the annual export quota for this species be restricted to fewer than 1000 individuals per year.
The collection of this species should be controlled to ensure a sustainable trade of this species. It has been recommended that the trade quota for the export of this species be reduced to 1,000 individuals per year.
Furthermore, the Malagasy rainbow frog is potentially able to breed in captivity, and research into captive breeding techniques for this species is ongoing at the Zoological Society of London. The IUCN Technical Guidelines for the Management of Ex situ Populations, part of the IUCN Red List of Threatened Species, recommend that all Critically Endangered species should have an ex situ population managed to guard against the extinction of the species. An ex situ population is ideally a breeding colony of a species maintained outside of its natural habitat, giving rise to individuals from that species that are sheltered from problems associated with their situation in the wild. This can be located within the species’ range or in a foreign country that has the facilities to support a captive breeding programme for that species. Since Malagasy rainbow frog is categorised as Critically Endangered, the possibility of a captive breeding programme for this species should be investigated. Captive animals could then be used both for reintroductions to supplement wild populations, and to provision a sustainable pet trade.
Furthermore, the Malagasy rainbow frog is potentially able to breed in captivity, and research into captive breeding techniques for this species is ongoing at the Zoological Society of London. The IUCN Technical Guidelines for the Management of Ex situ Populations, part of the IUCN Red List of Threatened Species, recommend that all Critically Endangered species should have an ex situ population managed to guard against the extinction of the species. An ex situ population is ideally a breeding colony of a species maintained outside of its natural habitat, giving rise to individuals from that species that are sheltered from problems associated with their situation in the wild. This can be located within the species’ range or in a foreign country that has the facilities to support a captive breeding programme for that species. Since Malagasy rainbow frog is categorised as Critically Endangered, the possibility of a captive breeding programme for this species should be investigated. Captive animals could then be used both for reintroductions to supplement wild populations, and to provision a sustainable pet trade.
Franco is herpetologist with extensive knowledge of Madagascan amphibians
AmphibiaWeb: Information on amphibian biology and conservation [web application]. 2006. Berkeley, California: AmphibiaWeb. Available: amphibiaweb. Accessed: 08 December 2006.
Andreone, F. and Luiselli, L.M. 2003. Conservation priorities and potential threats influencing the hyper-diverse amphibians of Madagascar. Italian Journal of Zoology 70: 53-63.
Arkive. 2006. Electronic database accessible at: Arkive. Accessed on 24 November 2006.
Busse, K. and Böhme, W. 1992. Two remarkable frog discoveries of the genera Mantella (Ranidae: Mantellinae) and Scaphiophrynine (Microhylidae: Scaphiophrynae) from the west coast of Madagascar. Revue d'Aguar Herpetologie 19: 57-64.
Duellman, W. E. and Trueb, L. 1986. Biology of Amphibians. McGraw-Hill, New York.
Frost, Darrel R. 2006. Amphibian Species of the World: an Online Reference. Version 4 (17 August 2006). Electronic Database accessible at:. American Museum of Natural History, New York, USA.
Frost, D. R., Grant, T., Faivovich, J., Bain, R.H., Haas, A., Haddad, C. F. B., De Sá, R.O., Channing, A., Wilkinson, M., Donnellan, S.C., Raxworthy, C.J., Campbell, J.A., Blotto, B.L., Moler, P., Drewes, R.C., Nussbaum, R.A., Lynch, J.D., Green, D.M., and Wheeler, W.C. 2006. The Amphibian Tree of Life. Bulletin of the American Museum of Natural History 297: 1-370.
Glaw, F. and Vences, M. 1994. A Fieldguide to the Amphibians and Reptiles of Madagascar. Second Edition. Zoologisches Forschungsinstitut und Museum Alexander Koenig, Bonn.
Guibé, J. (1956a): La position systématique des genres Pseudohemisus et Scaphiophryne (Batraciens).- Bull. Mus. natn. Hist. nat., ser. 2, 28 (2): 180-182.
Halliday, T. and Adler, C. (eds.). 2002. The new encyclopedia of reptiles and amphibians. Oxford University Press, Oxford.
IUCN, Conservation International and NatureServe. 2006. Global Amphibian Assessment. Global Amphibian Assessment. Accessed on 08 December 2006.
Mattison, C. 1987. Frogs and toads of the world. Blandford Press, U.K.
Obst, F.J., Richter, K. and Jacob, U. 1984. The Completely Illustrated Atlas of Reptiles and Amphibians for the Terrarium. T.F.H. Publication Inc., N.J., U.S.A.
Raxworthy, C. & Glaw, F. 2004. Scaphiophryne gottlebei. In: IUCN 2006. 2006 IUCN Red List of Threatened Species. IUCN Red List of Threatened Species. Downloaded on 01 December 2006.
Raxworthy, C.J. and Nussbaum, R.A. 1996. Montane amphibian and reptile communities in Madagascar. Conservation Biology 10: 750-756.
Roelants, K., Gower, D. J., Wilkinson, M., Loader, S. P., Biju, S. D., Guillaume, K., Moiau, L. and Bossuyt, F. 2007. Global patterns of diversification in the history of modern amphibians. Proceedings of the National Academy of Sciences 104: 887-892.
Staniszewski, M. 2006. Madagascan Burrowing Frogs FAQ (On-line).. Accessed on 24 November 2006.
Vences M., Aprea G., Capriglione T., Andreone F., Odierna G. (2002). ''Ancient tetraploidy and slow molecular evolution in Scaphiophryne: ecological correlates of speciation mode in Malagasy relict amphibians.'' Chromosome Research, 10, 127-136.
Andreone, F. and Luiselli, L.M. 2003. Conservation priorities and potential threats influencing the hyper-diverse amphibians of Madagascar. Italian Journal of Zoology 70: 53-63.
Arkive. 2006. Electronic database accessible at: Arkive. Accessed on 24 November 2006.
Busse, K. and Böhme, W. 1992. Two remarkable frog discoveries of the genera Mantella (Ranidae: Mantellinae) and Scaphiophrynine (Microhylidae: Scaphiophrynae) from the west coast of Madagascar. Revue d'Aguar Herpetologie 19: 57-64.
Duellman, W. E. and Trueb, L. 1986. Biology of Amphibians. McGraw-Hill, New York.
Frost, Darrel R. 2006. Amphibian Species of the World: an Online Reference. Version 4 (17 August 2006). Electronic Database accessible at:
Frost, D. R., Grant, T., Faivovich, J., Bain, R.H., Haas, A., Haddad, C. F. B., De Sá, R.O., Channing, A., Wilkinson, M., Donnellan, S.C., Raxworthy, C.J., Campbell, J.A., Blotto, B.L., Moler, P., Drewes, R.C., Nussbaum, R.A., Lynch, J.D., Green, D.M., and Wheeler, W.C. 2006. The Amphibian Tree of Life. Bulletin of the American Museum of Natural History 297: 1-370.
Glaw, F. and Vences, M. 1994. A Fieldguide to the Amphibians and Reptiles of Madagascar. Second Edition. Zoologisches Forschungsinstitut und Museum Alexander Koenig, Bonn.
Guibé, J. (1956a): La position systématique des genres Pseudohemisus et Scaphiophryne (Batraciens).- Bull. Mus. natn. Hist. nat., ser. 2, 28 (2): 180-182.
Halliday, T. and Adler, C. (eds.). 2002. The new encyclopedia of reptiles and amphibians. Oxford University Press, Oxford.
IUCN, Conservation International and NatureServe. 2006. Global Amphibian Assessment. Global Amphibian Assessment. Accessed on 08 December 2006.
Mattison, C. 1987. Frogs and toads of the world. Blandford Press, U.K.
Obst, F.J., Richter, K. and Jacob, U. 1984. The Completely Illustrated Atlas of Reptiles and Amphibians for the Terrarium. T.F.H. Publication Inc., N.J., U.S.A.
Raxworthy, C. & Glaw, F. 2004. Scaphiophryne gottlebei. In: IUCN 2006. 2006 IUCN Red List of Threatened Species. IUCN Red List of Threatened Species. Downloaded on 01 December 2006.
Raxworthy, C.J. and Nussbaum, R.A. 1996. Montane amphibian and reptile communities in Madagascar. Conservation Biology 10: 750-756.
Roelants, K., Gower, D. J., Wilkinson, M., Loader, S. P., Biju, S. D., Guillaume, K., Moiau, L. and Bossuyt, F. 2007. Global patterns of diversification in the history of modern amphibians. Proceedings of the National Academy of Sciences 104: 887-892.
Staniszewski, M. 2006. Madagascan Burrowing Frogs FAQ (On-line).
Vences M., Aprea G., Capriglione T., Andreone F., Odierna G. (2002). ''Ancient tetraploidy and slow molecular evolution in Scaphiophryne: ecological correlates of speciation mode in Malagasy relict amphibians.'' Chromosome Research, 10, 127-136.
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