88.
Toad Skinned Frog
(Indirana phrynoderma)
CR
Overview

The toad skinned frog belongs to a family that has been evolving independently in India for almost 50 million years. It is a ground-dwelling species, living on the forest floor in the Anamalai Hills of the Western Ghats. It has been little-studied since its formal discovery in 1882, although recent monitoring has indicated that it is declining across its range. It is thought to breed on wet rocks around streams and produce finless tadpoles that develop on these rocks. Despite its presence in protected areas, the species is threatened by habitat destruction and degradation.

Urgent Conservation Actions
Continued monitoring of its wild population dynamics; habitat conservation working with local communities; a captive breeding programme should be investigated.
Distribution
Anamalai Hills, India.
Associated Blog Posts
18th Sep 13
My name is Arun Kanagavel and I have been working in the Western Ghats Biodiversity Hotspot in India on herpetofauna and with local communities to integr...  Read

Evolutionary Distinctiveness
Order: Anura
Family: Ranixalidae

The toad skinned frog, along with its nine other close relatives in the genus Indirana has previously been placed in the family Ranidae (the “true frogs”) under the genus Rana (also referred to as the “true frogs”). The true frogs have the widest range of any family among the frogs and toads, found in nearly all regions of the world except Antarctica and most common in Africa and southeastern Asia. This family was formerly the largest within the frogs and toads, containing well over 600 species. It has recently been split into several different families, one of these being the Ranixalidae (or the “Indian frogs”).

The Indian frogs are a family within the sub order Neobatrachia or the “modern frogs and toads”, which contains all the more recently evolved groups. They diverged from all other species of amphibian almost 50 million years ago – 15 million years after the extinction of the dinosaurs and around the same time as the common ancestor of the porcupine and the chinchilla. This family exhibits a number of interesting characteristics, including sucking discs on the tips of the digits, vocal sacs either side of the throat and tadpoles that possess finless tails and develop on the surfaces of wet rocks next to streams. They are generally thought to be terrestrial (or ground-dwelling) species.

Description
Small in size, measuring only 35 mm in length. Its back is brown or greyish brown in colour with darker markings, probably providing good camouflage when the frog is surrounded by decaying leaves on the forest floor where it lives. It has a brown stomach with whitish markings. This species is also commonly known as the toad-skinned frog because its skin is covered in prominent warts and bumps of various sizes and it has a number of glandular folds across its back.

The broad head has a rounded snout and a dark tympanum (or eardrum). Approximately half the diameter of the eye is clearly visible either side of the head. The forelimbs are short with moderately long fingers and the tips of the fingers are dilated into disc-like suckers. Adults have long, muscular legs and the digits on both pairs of limbs are unwebbed.

Tadpoles display a very long tail which lacks a fin and have external gills when hatched. The mouth of the tadpole is beaky and contains small, corn-like teeth.
Ecology
Although it was formally discovered in 1882, very little is known of the ecology of this species because it has not been studied in any detail. However, it is thought that it breeds in a similar way to its close relative, the Gundia Indian frog, with mating taking place on wet rocks next to streams. The finless tadpoles are probably found on wet rock surfaces next to streams where they may scour the rock surfaces for algae or other organic material.

The diet is not known for certain, although it probably hunts small to medium sized invertebrates in the leaf litter of the forest floor.
Habitat
A terrestrial (or ground-dwelling) species associated with leaf litter in moist tropical forest.
Distribution
The species is only known for definite from a restricted area in the Anamalai Hills of the Western Ghats in India. It is found at an elevation of around 500 metres above sea level. It has also been reported from Maharashtra, but this record requires further investigation and is therefore not included in this account.
Population Estimate
An accurate population estimate is currently unavailable, however the species is known to be rare.
Population Trend

Little information on population status is currently available for the toad skinned frog, although it is very rare and is declining at its only known site.

Status
Listed as Critically Endangered on the IUCN Red List of Threatened Species 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 outside of Indira Ghandi National Park.
Threats
The major threat to this species is deforestation of its known habitat by local people for subsistence purposes and firewood collection.
Conservation Underway

The toad skinned frog is present in Indira Ghandi National Park and the adjoining Reserve Forest of Valparai. It was included in recent field studies in the late 1990s by Dr S.P. Vijaykumar (1999 and ongoing) and Dr S.D. Biju (1997), who incidentally co-discovered the purple frog (Nasikabatrachus sahyadrensis – EDGE amphibian rank 4) in 2003. This species is formally protected by national legislation.

Projects

The toad skinned frog (Indirana phrynoderma) is a rare, endemic, ground-dwelling species, which belongs to the evolutionarily distinct family of Ranixalidae. Recorded only from Indira Gandhi Wildlife Sanctuary (IGWLS) and the adjoining reserve forests of Valparai, this species is Critically Endangered, due to its point endemism and ongoing threats including habitat destruction. This project aims to generate baseline information on the species and explore opportunities for habitat conservation with local communities through outreach initiatives

Conservation Proposed

Further studies are required to investigate the life history and habitat requirements of this species, in addition to continued survey work to monitor its population dynamics.

Habitat conservation is a priority within the restricted range of this species, which should ideally include a community conservation programme gathering support from local people who carry out subsistence activities on the land. Improved protected area management that reduced destructive land uses within the Indira Ghandi National Park and the Reserve Forest of Valparai would be beneficial to this species, and this may involve providing support to park rangers and providing alternative sources of fuel wood for local people. This may engender new methods of sustainable land management in this area, allowing for traditional land uses and the conservation of some important habitat for the toad skinned frog and many other species found in these protected areas.

In addition to conserving native habitat for this species, 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 in the specie’s range or in a foreign country that has the facilities to support a captive breeding programme for that species. Since the toad skinned frog is categorised as Critically Endangered, the possibility of a captive breeding programme for this species should be investigated.

Associated EDGE Community members

A conservation biologist working on herpetofauna and with local communities in the India

Links
References
AmphibiaWeb: Information on amphibian biology and conservation [web application]. 2006. Berkeley, California: AmphibiaWeb. Available: amphibiaweb. Accessed: 08 December 2006.

Biju, S.D. 2001. A synopsis to the frog fauna of the Western Ghats, India. Occasional Publication 1. ISCB : 1-24.

Biju, S.D., Vijayakumar, S.P. & Dutta, S. 2004. Indirana phrynoderma. In: IUCN 2006. 2006 IUCN Red List of Threatened Species. IUCN Red List of Threatened Species. Downloaded on 01 August 2007.

Boulenger, G.A. 1882. Catalogue of the Batrachia Gradientia s. Caudata and Batrachia Apoda in the collection of the British Museum. British Museum of Natural History, London.

Dubois, A. 1986. Diagnose preliminaire d'an nonvean genre de Ranoidea (Amphibians, Anoures) du snd de l'Inde. Alytes 4(3): 113-118.

Dutta, S.K. 1997. Amphibians of India and Sri Lanka. Odyssey Publishing House, Bhubaneswar.

Frost, D. R., T. Grant, J. Faivovich, R. H. Bain, A. Haas, C. F. B. Haddad, R. O. De Sá, A. Channing, M. Wilkinson, S. C. Donnellan, C. J. Raxworthy, J. A. Campbell, B. L. Blotto, P. Moler, R. C. Drewes, R. A. Nussbaum, J. D. Lynch, D. M. Green, and W. C. Wheeler. 2006. The Amphibian Tree of Life. Bulletin of the American Museum of Natural History 297: 1-370.

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.

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.

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.

Padhye, A.D. and Ghate, H.V. 2002. An overview of amphibian fauna of Maharashtra State. ZOO's Print Journal 17(3): 735-740.

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.

if you can provide new information to update this species account or to correct any errors, please email us at info@edgeofexistence.org


Forum comments

There are as yet no comments for this species.

Add a comment

You must log in to post. If you don't have a login, it's easy to register.