Portal:Amphibians
The Amphibian Portal
Amphibians are ectothermic, anamniotic, four-limbed vertebrate animals that constitute the class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all tetrapods excluding the amniotes (tetrapods with an amniotic membrane, such as modern reptiles, birds and mammals). All extant (living) amphibians belong to the monophyletic subclass Lissamphibia, with three living orders: Anura (frogs and toads), Urodela (salamanders), and Gymnophiona (caecilians). Evolved to be mostly semiaquatic, amphibians have adapted to inhabit a wide variety of habitats, with most species living in freshwater, wetland or terrestrial ecosystems (such as riparian woodland, fossorial and even arboreal habitats). Their life cycle typically starts out as aquatic larvae with gills known as tadpoles, but some species have developed behavioural adaptations to bypass this.
Young amphibians generally undergo metamorphosis from an aquatic larval form with gills to an air-breathing adult form with lungs. Amphibians use their skin as a secondary respiratory interface and some small terrestrial salamanders and frogs lack lungs and rely entirely on their skin. They are superficially similar to reptiles like lizards, but unlike reptiles and other amniotes, require access to water bodies to breed. With their complex reproductive needs and permeable skins, amphibians are often ecological indicators to habitat conditions; in recent decades there has been a dramatic decline in amphibian populations for many species around the globe.
The earliest amphibians evolved in the Devonian period from tetrapodomorph sarcopterygians (lobe-finned fish with articulated limb-like fins) that evolved primitive lungs, which were helpful in adapting to dry land. They diversified and became ecologically dominant during the Carboniferous and Permian periods, but were later displaced in terrestrial environments by early reptiles and basal synapsids (predecessors of mammals). The origin of modern lissamphibians, which first appeared during the Early Triassic, around 250 million years ago, has long been contentious. The most popular hypothesis is that they likely originated from temnospondyls, the most diverse group of prehistoric amphibians, during the Permian period. Another hypothesis is that they emerged from lepospondys. A fourth group of lissamphibians, the Albanerpetontidae, became extinct around 2 million years ago. (Full article...)
Selected frog article
The Hyperoliidae, or sedge frogs and bush frogs, are a large family of small to medium-sized, brightly colored frogs which contains more than 250 species in 19 genera. Seventeen genera are native to sub-Saharan Africa. In addition, the monotypic genus Tachycnemis occurs on the Seychelles Islands, and the genus Heterixalus (currently 10 species) is endemic to Madagascar.
Hyperoliids range from 1.5 to 8 cm (0.59 to 3.15 in) in body length. Many species have smooth, brightly patterned skin that almost looks enameled.
Most hyperoliids are arboreal, but some are terrestrial, including several Kassina species that move by walking or running rather than hopping. Diets vary widely, with examples including Paracassina, which specializes on snails, and Afrixalus fornasini, the only terrestrial frog known to prey on eggs of other species of anurans. (Full article...)Selected salamander article
List of selected salamander articles
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Did you know? –
- ... that the Central American frog Duellmanohyla soralia is critically endangered and its population decline is due, at least in part, to the fungal disease chytridiomycosis?
- ... that the desert rain frog leaves distinctive footprints on the dunes and a little pile of sand showing the location of its burrow?
- ... that Pseudophilautus hypomelas, a small shrub frog not seen for more than 130 years and believed to be extinct, was rediscovered in the Peak Wilderness of Sri Lanka?
Selected amphibian type
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Toad is a common name for certain frogs, especially of the family Bufonidae, that are characterized by dry, leathery skin, short legs, and large bumps covering the parotoid glands.
A distinction between frogs and toads is not made in scientific taxonomy, but is common in popular culture (folk taxonomy), in which toads are associated with drier, rougher skin and more terrestrial habitats. (Full article...)List of selected amphibian type articles
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Photograph: Benny TrappThe Spanish painted frog (Discoglossus jeanneae) is a species of frog in the family Alytidae. Endemic to Spain, it mostly lives in open areas, pine groves and shrublands. It feeds mostly on insects and worms. -
Photograph: Richard Bartz -
Photo: Richard BartzThe common frog (Rana temporaria) is found throughout much of Europe. Adults have a body length of 6 to 9 cm (2.4 to 3.5 in) and vary in colour, with the ability to lighten and darken their skin to match their surroundings. They will feed on any invertebrate of a suitable size and, apart from the breeding season, live solitary lives. -
Photograph credit: Charles James SharpThe marsh frog (Pelophylax ridibundus) is a species of amphibian native to Europe and parts of Asia. It is the largest type of frog in most of its range, growing to a snout-to-vent length of around 100 mm (4 in); tadpoles can reach up to 190 mm (7.5 in) in length, but this usually occurs in places with long winters where the tadpole has time to grow. Marsh frogs hibernate during the winter, either underwater or in burrows, and are able to use the Earth's magnetic field to locate breeding ponds. This marsh frog was photographed in Kampinos National Park, Poland. -
Photograph credit: RushenbRaorchestes parvulus is a small bush frog native to tropical southeastern Asia. Although the reproductive strategy of this species has not been studied, members of the family typically make a foam nest while mating in vegetation overhanging a stream. They create the foam by beating their legs, and the eggs are deposited into the nest and covered with seminal fluid before the foam hardens into a protective casing. When the eggs hatch, the young push their way out of the nest and fall into the water below.
This picture shows a male R. parvulus frog, photographed in Phu Kradueng National Park, Thailand, calling by inflating its vocal sac. -
Photograph: Benny TrappThe Albanian water frog (Pelophylax shqipericus) is a species of true frog in the family Ranidae. It is native to Albania and Montenegro, where it lives in aquatic environments. The frogs are medium-sized. Males sometimes bear a distinctive bright green stripe down the length of the backbone, but otherwise are green to light brown in overall colouring with large black or dark brown spots. Females are olive green or light brown in colour and also bear brown or black large spots. The species is endangered and known populations are currently in decline. -
The fire salamander (Salamandra salamandra) is a European salamander species with a long lifespan. These nocturnal animals generally eat various insects, spiders, earthworms and slugs, but they also occasionally eat newts and young frogs. -
The edible frog (Pelophylax kl. esculentus) is a fertile hybrid of the pool and marsh frogs which is commonly found in Europe. The species is commonly used in food, including the French delicacy frog legs. -
Photograph: Benny TrappThe Iberian midwife toad (Alytes cisternasii) is a species of frog in the family Alytidae found in Portugal and western Spain. Its natural habitats are temperate forests and shrubland, Mediterranean-type shrubby vegetation, intermittent rivers and freshwater marshes, pastureland, and aquaculture ponds. The species is affected by habitat loss, and the IUCN lists it as being "Near Threatened". -
Photograph credit: Charles J. SharpMantella baroni, commonly known as Baron's mantella, variegated golden frog or Madagascar poison frog, is a species of frog in the family Mantellidae. It is native to Madagascar and is seen here in Ranomafana National Park in the southeastern part of the country. The species was described in 1888 by George Albert Boulenger, who named it after its collector, Richard Baron. It has been classified as a least-concern species by the International Union for Conservation of Nature due to its relatively wide distribution, but is threatened by habitat loss. The frog's diet includes mites, which cause it to accumulate a high alkaloid concentration in its skin, making it toxic. The bright colours may serve as a warning sign to potential predators of the frog's toxicity. -
Photo: Benny TrappAn Italian tree frog (Hyla intermedia) with an inflated vocal sac. Vocal sacs, flexible membranes of skin possessed by most male frogs, are generally used to amplify mating or advertisement calls. However, some species in the family Rhinodermatidae may also use the sac to store or transport their tadpoles. -
Photo credit: Patrick CoinA terrestrial subadult Eastern newt or red eft (Notophthalmus viridescens). Salamanders of the family Salamandridae with aquatic adult stages are called newts. Some newts, including the Eastern newt, have a juvenile terrestrial stage called the eft. The red eft has bright aposematic coloration to warn predators of its highly toxic skin. -
Photo credit: LiquidGhoulThe Red-eyed Tree Frog (Litoria chloris) is a species of tree frog native to eastern Australia; ranging from north of Sydney to Proserpine in mid-northern Queensland. These frogs typically reach a size of 65 millimetres (2.6 in). Its skin secretions have been found to destroy HIV, without harming healthy T cells. -
Photo: QuartlDendrobates azureus, commonly known as the blue poison dart frog or okopipi, is a poison dart frog found in the forests surrounded by the Sipaliwini Savanna in southern Suriname. Authorities have recently treated it as a variant of Dendrobates tinctorius rather than a distinct species as before. -
Photograph credit: RushenbWallace's flying frog (Rhacophorus nigropalmatus) is a moss frog found in tropical southeastern Asia. It is named after the British naturalist Alfred R. Wallace, who collected the first known specimen of the species. It lives almost exclusively in trees, and when threatened, or in search of prey, will leap from a branch and splay its four webbed feet; the membranes between its toes and the loose skin flaps on its sides catch the air as it falls, helping it to glide. This individual was photographed in Khao Sok National Park, Thailand.
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Selected toad article
Selected caecilian article
The Ichthyophiidae are the family of Asiatic tailed caecilians or fish caecilians found in South and Southeast Asia as well as southernmost China.
They are primitive caecilians, lacking many of the derived characters found in the other families. For example, their mouths are not recessed underneath their heads, they possess tails, and they have numerous scales on their bodies. However, they have two sets of muscles for closing the jaw, a feature unique to caecilians, but absent in the related family Rhinatrematidae.
They lay their eggs in cavities in moist soil, where they hatch into larvae that seek out streams or underground seepages, before metamorphosing into adults. Some evidence indicates the females may protect their eggs until they hatch. (Full article...)Need help?
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