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Order: Anura
Family: Heleophrynidae
The ghost frogs of the family Heleophrynidae comprise only 6 species and represent the most basal or ancient members of the “Neobatrachia” (the modern frogs and toads) – a suborder of within the order “Anura” (the frogs and toads) containing all of the more recently evolved families within “Anura”. The older lineages, of which they are many fewer (just 9 out of the 45 currently recognised families of frogs and toads), are found in the suborder “Archaebatrachia” (the ancient frogs and toads). Despite being classed with the modern frogs and toads, the ghost frogs diverged from their closest ancestors over 160 million years ago in the Jurassic period.
The Table Mountain ghost frog therefore has very few close relatives and is one of the only surviving members of the earliest lineage that gave rise to the modern frogs and toads. The closest ancestors of this species were the first modern frogs. Prior to 1988, the ghost frogs were thought to be the only African representatives of the Leptodactylidae (Leptodactylid frogs – a family of frogs otherwise entirely found in the Americas) and they were placed in a subfamily called the Heleophryninae. However, they have been moved to their own, much smaller family based on numerous morphological distinctions and are a much more ancient lineage than the Leptodactylidae. In fact, the Leptodactylid frogs diverged from their nearest common ancestors over 100 million years after ghost frogs split from the rest of the modern frogs and toads. The fact that the closest relatives of the ghost frogs are thought to be in South America (the Leptodactylid frogs) and Australia (the Myobatrachidae or Australian toadlets and waterfrogs) provides further evidence of continental drift and is indicative of the great age of this amphibian family.
The Table Mountain ghost frog therefore has very few close relatives and is one of the only surviving members of the earliest lineage that gave rise to the modern frogs and toads. The closest ancestors of this species were the first modern frogs. Prior to 1988, the ghost frogs were thought to be the only African representatives of the Leptodactylidae (Leptodactylid frogs – a family of frogs otherwise entirely found in the Americas) and they were placed in a subfamily called the Heleophryninae. However, they have been moved to their own, much smaller family based on numerous morphological distinctions and are a much more ancient lineage than the Leptodactylidae. In fact, the Leptodactylid frogs diverged from their nearest common ancestors over 100 million years after ghost frogs split from the rest of the modern frogs and toads. The fact that the closest relatives of the ghost frogs are thought to be in South America (the Leptodactylid frogs) and Australia (the Myobatrachidae or Australian toadlets and waterfrogs) provides further evidence of continental drift and is indicative of the great age of this amphibian family.
The Table Mountain ghost frog is a moderate sized species of frog characterised by a squat, compressed body that enables this species to conceal itself in narrow rock crevices during the day when it is inactive. Adult females are about 60 mm in length, while adult males are slightly smaller at a length of about 50 mm. These frogs have highly webbed feet as an adaptation for strong swimming, although they are relatively poor jumpers. The Table Mountain ghost frog possess a rudimentary thumb structure, large eyes with vertical pupils, and the tips of the fingers and toes are expanded and spatulate (or disc-like). Their disproportionately large toe discs help them to cling onto rocks surrounding their streams. Adult male frogs develop folds of loose skin during the predominantly aquatic breeding season that increase their respiratory surface area so they can take up more oxygen from the water. Both sexes develop spiny structures on their bodies that facilitate better contact during amplexus (the mating embrace). Adult Table Mountain ghost frogs are striking in colouration consisting of a pale green background with purple to reddish brown blotches.
The tadpoles of Table Mountain ghost frogs can be identified by brown stipple on the fins and body. They possess a sucker-like mouthparts, which are used for algal feeding and securing a grip on rocky substrates in swift-moving streams. They can also use their mouths to climb up wet, vertical rock surfaces around their streams at night. Hewitt’s ghost frog tadpoles also have strong, muscular tails for swimming in fast-flowing water.
The tadpoles of Table Mountain ghost frogs can be identified by brown stipple on the fins and body. They possess a sucker-like mouthparts, which are used for algal feeding and securing a grip on rocky substrates in swift-moving streams. They can also use their mouths to climb up wet, vertical rock surfaces around their streams at night. Hewitt’s ghost frog tadpoles also have strong, muscular tails for swimming in fast-flowing water.
The ghost frogs inhabit mountain streams within their distribution, and have morphological adaptation suited to surviving on the rocks around these streams. They have very large toe discs in comparison to their size, which helps to cling onto rocks. The mouthparts of the tadpoles are modified into a sucking disc, to allow them to cling to substrates, and remain still, while they are feeding.
The Table Mountain ghost frog is a rare species known from few adults and only a slightly larger number of tadpoles, which may be more easily located. Egg masses have never been found, but breeding occurs in the spring and summer months (November to February in the Southern Hemisphere) during the period of low stream flow. This may be beneficial to ensure that eggs will not be laid in streams that will later dry up. The advertisement mating call is a brief click, 30 milliseconds long, with an emphasised frequency of 1.8 kHz, and males have been recorded calling in December. During the mating season, males develop pronounced secondary sexual characteristics. These include a number of small black spines on the outside surface of the forearms, on the back and on the top of the back legs.
Tadpoles of this species develop slowly in the cold water of their mountain streams, generally over a period of 12 months or more, and so it is important that there is perennial water (water available all year round) to allow the larvae to develop. They are torrent adapted, using their sucking mouthparts to gain purchase on the rocky surfaces of the streambed. Tadpoles feed on algae covering these rocks. After metamorphosis, individuals leave the streams before the onset of winter rains.
Adult behaviour in the Table Mountain ghost frog has not been well-studied. It is known, however, that adults do stray from streams, traveling across land. Non-breeding adults have been found in damp, sheltered habitat some distance from streams, including in caves. This frog has been called a “trogloxene” species, which is defined as an occasional cave visitor that enters caves for various reasons but does not accomplish its full life cycle within them.
The Table Mountain ghost frog is a rare species known from few adults and only a slightly larger number of tadpoles, which may be more easily located. Egg masses have never been found, but breeding occurs in the spring and summer months (November to February in the Southern Hemisphere) during the period of low stream flow. This may be beneficial to ensure that eggs will not be laid in streams that will later dry up. The advertisement mating call is a brief click, 30 milliseconds long, with an emphasised frequency of 1.8 kHz, and males have been recorded calling in December. During the mating season, males develop pronounced secondary sexual characteristics. These include a number of small black spines on the outside surface of the forearms, on the back and on the top of the back legs.
Tadpoles of this species develop slowly in the cold water of their mountain streams, generally over a period of 12 months or more, and so it is important that there is perennial water (water available all year round) to allow the larvae to develop. They are torrent adapted, using their sucking mouthparts to gain purchase on the rocky surfaces of the streambed. Tadpoles feed on algae covering these rocks. After metamorphosis, individuals leave the streams before the onset of winter rains.
Adult behaviour in the Table Mountain ghost frog has not been well-studied. It is known, however, that adults do stray from streams, traveling across land. Non-breeding adults have been found in damp, sheltered habitat some distance from streams, including in caves. This frog has been called a “trogloxene” species, which is defined as an occasional cave visitor that enters caves for various reasons but does not accomplish its full life cycle within them.
The Table Mountain ghost frog lives in forest and fynbos heathland, breeding in clear perennial streams in forested gorges, valleys and ravines on Table Mountain. It is confined to a very small area of approximately 7-8 km sq. on the eastern, southern and marginally western slopes of Table Mountain. Tadpoles have been recorded at Window Gorge, Skeleton Gorge, Nursery Ravine, Cecilia Ravine, the Original Disa Stream, Disa Gorge, and Disa Stream. The species is endemic to this region and individuals have been recorded only in wet mountain fynbos – areas of high rainfall (300-600 mm per year). Within their broader range, the Table Mountain ghost frog is concentrated in wooded ravines and valleys in clear, swift-flowing perennial streams. The year-round water supply is necessary to facilitate the approximately year-long development of tadpoles. Typical stream consists of steep, algae-covered rocks in areas of fast-moving, cascading water. Adults have been recorded traveling away from streams over open land, and have occasionally been found in caves.
This species is endemic to the southern, eastern, and marginally western slopes of Table Mountain, in the Western Cape Province of extreme south-western South Africa. It occurs at an altitude of 240-1,060 metres above sea level.
Rose’s ghost frog is a rare and elusive species that appears to be declining and survives in very low population densities. For example, it is estimated that the number of tadpoles in Skeleton Gorge has decreased by 50% since 1980.
This species is believed to be in decline by the IUCN Red List of Threatened Species.
The Table Mountain ghost frog is listed as Critically Endangered in the IUCN Red List of Threatened Species because its extent of occurrence is less than 100 km², its area of occupancy of less than 10 km², all individuals are in a single location, and there is a continuing decline in the extent and quality of its habitat, area of occupancy, number of locations, and number of mature individuals.
The main threats to the Table Mountain ghost frog are the spread of alien vegetation, frequent fires, and the construction of water storage reservoirs on the mountain affecting the consistency of stream-flow. Intensive eco-tourism is also a potential threat given that Table Mountain is one of South Africa’s most visited natural locations.
In addition, the tiny range of this species makes it extremely vulnerable to threats such as invasive species and disease. The fungal disease chytridiomycosis has been found in some populations of the Table Moutain ghost frog in recent years, which could spell doom for this species. Although its distribution currently exists within the confines of protected lands (the National Botanic Gardens and Department of Forestry), many threats persist, such as plantations of exotic pines, Eucalyptus and poplars which have clogged the streams that serve as the primary habitat of the Table Mountain ghost frog, creating stagnant waterways not conducive to the frog’s life cycle. This species has already become locally extinct in some areas of Table Mountain. Poor forestry practices may also lead to the clogging of these waterways.
At the beginning of the 20th century, dams were constructed along many waterways on Table Mountain, including those that function as habitat for the Table Moutain ghost frog. Reduced water flow from these dams may lead to a decline in this torrent-adapted species. Global climate change may also threaten the survival of this species as the number of dry years increases, reducing the availability of sufficient perennial streams.
At the beginning of the 20th century, dams were constructed along many waterways on Table Mountain, including those that function as habitat for the Table Moutain ghost frog. Reduced water flow from these dams may lead to a decline in this torrent-adapted species. Global climate change may also threaten the survival of this species as the number of dry years increases, reducing the availability of sufficient perennial streams.
The whole of this species' range is incorporated in the Table Mountain National Park, part of the Cape Floristic Region World Heritage Site and Conservation International (CI) Hotspot. CI’s Critical Ecosystem Partnership Fund provides support for conservation projects in this (and other) hotspots. A monitoring programme by Western Cape Nature Conservation is in place.
The maintenance of its remaining breeding and non-breeding habitat is essential. This may be possible through working with local forestry services to manage plantations around Table Mountain ghost frog habitat more sustainably by creating buffer zones of native vegetation around the streams. At present, pine plantations are extending right down to the banks of the streams and this is having a detrimental effect upon habitat quality for this species.
There is also a need for continued monitoring of known populations and survey work to search for any additional populations. Disease screening and monitoring of this species is also an important priority because the virulent amphibian disease chytridiomycosis has already been found affecting wild populations of Table Mountain ghost frogs. This will contribute important information for the wild management of this species.
Preservation of the Table Mountain ghost frog will also be aided by continued efforts to maintain swift-flowing perennial streams in the Table Mountain region. It is imperative that a policy continues to mandate that the dams permit a continuous flow downstream to maintain and preserve this species' habitat. It has also been suggested that translocation of individuals may be of great importance as many suitable sites are currently uninhabited by the Table Mountain ghost frog.
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 within the species range or in a foreign country that has the facilities to support a captive breeding programme for that species. Further investigation is therefore required into the possibilities of establishing a captive breeding programme for the Table Mountain ghost frog, which may be a difficult process because it is not considered to be a particularly good species for captivity, although a captive breeding effort for the Natal ghost frog is already underway. This could provide individuals for translocation to suitable sites that have already lost their former populations of this species.
There is also a need for continued monitoring of known populations and survey work to search for any additional populations. Disease screening and monitoring of this species is also an important priority because the virulent amphibian disease chytridiomycosis has already been found affecting wild populations of Table Mountain ghost frogs. This will contribute important information for the wild management of this species.
Preservation of the Table Mountain ghost frog will also be aided by continued efforts to maintain swift-flowing perennial streams in the Table Mountain region. It is imperative that a policy continues to mandate that the dams permit a continuous flow downstream to maintain and preserve this species' habitat. It has also been suggested that translocation of individuals may be of great importance as many suitable sites are currently uninhabited by the Table Mountain ghost frog.
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 within the species range or in a foreign country that has the facilities to support a captive breeding programme for that species. Further investigation is therefore required into the possibilities of establishing a captive breeding programme for the Table Mountain ghost frog, which may be a difficult process because it is not considered to be a particularly good species for captivity, although a captive breeding effort for the Natal ghost frog is already underway. This could provide individuals for translocation to suitable sites that have already lost their former populations of this species.
Werner is a herpetologist form South Africa, focusing on conserving of threaten amphibians species.
Behler, J.L. and Behler, D.A. 2005. Frogs: A Chorus of Colors. Sterling Publishing, NY, U.S.A.
Branch, W.R. (ed.). 1988. South African Red Data Book - Reptiles and Amphibians. South African National Scientific Programmes Report 151.
Channing, A. 2001. Amphibians of Central and Southern Africa. Cornell University Press, Ithaca and London.
Duellman, W. E. and Trueb, L. 1986. Biology of Amphibians. McGraw-Hill, New York.
De Villiers, A.L. 1997. Monitoring the distribution and conservation status of threatened amphibians in the southwestern Cape. In: Proceedings of the Third H.A.A. Symposium on African Herpetology, 1993, Pretoria, pp. 142-148. Herpetological Association of Africa, Stellenbosch, South Africa.
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.
Groombridge, B. (ed.) 1994. 1994 IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland.
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.
McLachlan, A. 1978. South African Red Data Book - Reptiles and Amphibians. South African National Scientific Programmes Report 23. CSIR, Pretoria.
Minter, L., Channing, A. & Harrison, J. 2004. Heleophryne rosei. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. IUCN Red List of Threatened Species.. Downloaded on 20 September 2007.
Minter, L.R., Burger, M., Harrison, J.A., Braack, H.H., Bishop, P.J. and Knoepfer, D. 2004. Atlas and Red Data Book of the Frogs of South Africa, Lesotho and Swaziland. SI/MAB Series No. 9, Washington, D.C.
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.
Passmore, N.I. and Carruthers, V.C. 1995. South African Frogs. 2nd Edition. Southern Book Publishers and Witwatersrand University Press, Johannesburg.
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.
Branch, W.R. (ed.). 1988. South African Red Data Book - Reptiles and Amphibians. South African National Scientific Programmes Report 151.
Channing, A. 2001. Amphibians of Central and Southern Africa. Cornell University Press, Ithaca and London.
Duellman, W. E. and Trueb, L. 1986. Biology of Amphibians. McGraw-Hill, New York.
De Villiers, A.L. 1997. Monitoring the distribution and conservation status of threatened amphibians in the southwestern Cape. In: Proceedings of the Third H.A.A. Symposium on African Herpetology, 1993, Pretoria, pp. 142-148. Herpetological Association of Africa, Stellenbosch, South Africa.
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.
Groombridge, B. (ed.) 1994. 1994 IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland.
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.
McLachlan, A. 1978. South African Red Data Book - Reptiles and Amphibians. South African National Scientific Programmes Report 23. CSIR, Pretoria.
Minter, L., Channing, A. & Harrison, J. 2004. Heleophryne rosei. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. IUCN Red List of Threatened Species.. Downloaded on 20 September 2007.
Minter, L.R., Burger, M., Harrison, J.A., Braack, H.H., Bishop, P.J. and Knoepfer, D. 2004. Atlas and Red Data Book of the Frogs of South Africa, Lesotho and Swaziland. SI/MAB Series No. 9, Washington, D.C.
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.
Passmore, N.I. and Carruthers, V.C. 1995. South African Frogs. 2nd Edition. Southern Book Publishers and Witwatersrand University Press, Johannesburg.
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.
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