Ghost frog

(Heleophrynidae)

Class: Amphibia

Order: Anura

Family: Heleophrynidae

Thumbnail description
Medium-sized frogs with triangular discs on the fingers and toes

Size
1.4–2.6 in (35–65 mm)

Number of genera, species
1 genus; 6 species

Habitat
Montane forest

Conservation status
Endangered: 1 species; Vulnerable: 1 species

Distribution
South Africa, Lesotho, and Swaziland

Evolution and systematics

No fossils are known. The family has its closest relatives in South America and Australia, which is interesting further evidence of continental drift and the great age of this family. Although it was placed earlier as a subfamily within the Leptodactylidae, it now is recognized as a distinct family. No subfamilies are recognized.

Physical characteristics

The large, triangular discs on the fingers and toes are characteristic, along with a vertical pupil and a dorsal color pattern usually consisting of large spots on a brown or green background. The adult males of the smaller species, such as Heleophryne orientalis, do not exceed 1.4 in (35 mm), while the females of larger species grow to more than 2.6 in (65 mm). The body is flattened with protruding eyes, and the limbs are thin and long. The pupil is vertical, the tongue is disc-shaped, and the upper jaw bears teeth. The frogs swim well, with toes that are nearly fully webbed in some species. Most species have large dark spots on a paler background. The background color is typically tan to pale gray, but dark brown, yellowish, or bright green individuals are found. The tadpoles are streamlined and cling to rocks in fast-flowing streams. Most tadpoles have no keratinized jaw sheaths, except Heleophryne rosei, which has only a lower jaw sheath.

Distribution

This family is endemic to the high mountains and escarpment of the Drakensberg range and its extensions in southern Africa. Species are found from sea level to 9,843 ft (3,000m). The recent loss of natural forest has caused streams to dry up, especially in areas where pines have been planted. Two species have very restricted ranges associated with pine plantations.

Habitat

Adults are found in forest or riverine forest. They may move 0.6 mi (1 km) or more from streams outside the breeding season, even into alpine grassland. The larvae are restricted to fast-flowing streams with rocky substrates. They are found attached to rocks in the fast current and also in quiet backwaters.

Behavior

The frogs congregate after the rains near waterfalls or other fast-flowing water once the rivers subside. After breeding, the adults stay near the stream to feed but will move long distances away from water until the next rainy season heralds a new breeding season. Adults remain concealed in cracks or in holes during the day, emerging at night to feed and breed.

Feeding ecology and diet

These frogs take a range of insects, arthropods, and snails. They readily eat smaller species of frogs.

Reproductive biology

During the breeding season the body skin becomes loose, forming large, slimy folds, with the toes fringing with web. Males move into the streams as sexual activity increases and remain aquatic until the breeding season ends. The loose skin provides additional surface area, so that the males can obtain oxygen from the water. The breeding season is from spring to mid-summer (October to January in southern Africa). The male calls from within the spray zone of a waterfall or concealed in a rock crack or under a large rock. In some species the call is loud, but in others it is quiet, audible only from 10 ft (3 m) or less. Eggs are laid in quiet backwaters, but they also may be laid out of water in seepage zones, singly in slow-flowing areas and small pools. Some species attach their eggs under rocks in a stream. The eggs develop into free-swimming tadpoles. There is no parental care. The tadpoles graze on algae growing on rocks, leaving grazing trails.

Conservation status

The family is endemic to the Drakensberg mountain chain running through South Africa, Lesotho, and Swaziland. Two species are common, with wide distributions, while one is classified as Vulnerable (Heleophryne rosei) and another as Endangered (Heleophryne hewitti) by the IUCN. H. hewitti is known from short sections of only four rivers, all within 6.2 mi (10 km) along the slopes of the Elandsberg Mountains. H. rosei is restricted to a few streams on one side of Table Mountain in Cape Town, South Africa.

Significance to humans

These animals are not used for food. Although the skin contains toxins that protect the animal from mammalian predators, these toxins are not significant for humans.

Species accounts

Resources

Channing, A. Amphibians of Central and Southern Africa. Ithaca: Cornell University Press, 2001.

[Article by: Alan Channing, PhD]

Ghost frogs
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Amphibia
Order:	Anura
Suborder:	Neobatrachia
Family:	Heleophrynidae Noble, 1931
Genus:	Heleophryne Sclater, 1898
Species
Heleophryne hewitti Heleophryne natalensis Heleophryne orientalis Heleophryne purcelli Heleophryne regis Heleophryne rosei
Distribution of Heleophrynidae (in black)

The Heleophrynidae, is a family of order Anura, commonly known as ghost frogs. The family consists of a single genus, Heleophryne, and six species. Ghost frogs live in swift-moving mountain streams in South Africa. The common name of "ghost frogs" may have been coined because of their occurrence in Skeleton Gorge.^[1]

Contents 1 Biology 2 Taxonomy 3 EDGE endangered species 4 References

Biology

Ghost frogs have morphological adaptation suited to surviving on the rocks around these streams. They are medium sized frogs, reaching a length of 6 centimetres (2.4 in), with flat bodies, enabling them to climb inside rocky crevices. 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.^[1]

Taxonomy

The ghost frogs are closely related to the Sooglossidae family, which inhabit the Seychelles. They may also be closely related to the Australian Myobatrachids.

Family HELEOPHRYNIDAE

• Genus Heleophrynus
  • Hewitt's Ghost Frog, Heleophryne hewitti Boycott, 1988
  • Natal Ghost Frog, Heleophryne natalensis Hewitt, 1913
  • Eastern Ghost Frog, Heleophryne orientalis FitzSimons, 1946
  • Purcell's Ghost Frog, Heleophryne purcelli Sclater, 1898
  • Royal Ghost Frog, Heleophryne regis Hewitt, 1910
  • Rose's Ghost Frog, Heleophryne rosei Hewitt, 1925

EDGE endangered species

On January 21, 2008, Evolutionarily Distinct and Globally Endangered (EDGE) identified nature's most "weird, wonderful and endangered species", stating that "the EDGE amphibians are amongst the most remarkable and unusual species on the planet and yet an alarming 85% of the top 100 are receiving little or no conservation attention." Their top ten species included the ghost frogs.^[2][3][4] hey

References

1. ^ ^{a b} Zweifel, Richard G. (1998). Cogger, H.G. & Zweifel, R.G.. ed. Encyclopedia of Reptiles and Amphibians. San Diego: Academic Press. pp. 104–105. ISBN 0-12-178560-2. 
2. ^ Reuters, Giant newt, tiny frog identified as most at risk
3. ^ guardian.co.uk, Drive to save weird and endangered amphibians
4. ^ guardian.co.uk/environment, Gallery: the world's strangest amphibians

• Cogger, H.G.; R.G. Zweifel, and D. Kirschner (2004). Encyclopedia of Reptiles & Amphibians Second Edition. Fog City Press. ISBN 1-877019-69-0. 

v • d • e Extant anuran families by suborder Kingdom Animalia · Phylum Chordata · Subphylum Craniata · Superclass Tetrapoda · Class Amphibia Archaeobatrachia Ascaphidae · Bombinatoridae · Discoglossidae · Leiopelmatidae Mesobatrachia Megophryidae · Pelobatidae · Pelodytidae · Pipidae · Scaphiopodidae · Rhinophrynidae Neobatrachia Amphignathodontidae · Aromobatidae · Arthroleptidae · Brachycephalidae · Bufonidae · Centrolenidae · Dendrobatidae · Heleophrynidae · Hemisotidae · Hylidae · Hyperoliidae · Leptodactylidae · Mantellidae · Microhylidae · Myobatrachidae · Petropedetidae · Ranidae · Rhacophoridae · Rhinodermatidae · Sooglossidae

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