Portal:Amphibians

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The Amphibian Portal

Anaschisma

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 lepospondyls. A fourth group of lissamphibians, the Albanerpetontidae, became extinct around 2 million years ago. (Full article...)

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Selected frog article

The common eastern froglet (Crinia signifera)

Myobatrachidae, commonly known as Australian ground frogs or Australian water frogs, is a family of frogs found in Australia and New Guinea. Members of this family vary greatly in size, from species less than 1.5 cm (0.59 in) long, to the second-largest frog in Australia, the giant barred frog (Mixophyes iteratus), at 12 cm (4.7 in) in length. The entire family is either terrestrial or aquatic frogs, with no arboreal species. (Full article...)

List of selected frog articles

Selected salamander article

The salamander is an amphibian of the order Urodela which, as with many real creatures, often has been ascribed fantastic and sometimes occult qualities by pre-modern authors (as in the allegorical descriptions of animals in medieval bestiaries) not possessed by the real organism. The legendary salamander is often depicted as a typical salamander in shape with a lizard-like form, but is usually ascribed an affinity with fire, sometimes specifically elemental fire. (Full article...)

List of selected salamander articles
Caudata Ambystomatidae Cryptobranchoidea Greater siren Salamandroidea Sexual selection in amphibians Sirenidae Urodela

Did you know? – show different entries

... that the caecilians Chthonerpeton indistinctum and Typhlonectes compressicauda (pictured) both give birth to live young?
...that the Desert Tree Frog is one of Australia's most widely distributed frogs?
... that eggs of the greenhouse frog are laid on land and have been found under a flower pot?
... that the black jumping salamander, the dwarf false brook salamander, the admirable false brook salamander, the Smith's false brook salamander and Thorius pennatulus are all endemic to Mexico, and critically endangered?
... that the male polkadot poison frog guards the eggs laid by the female and carries the newly hatched tadpoles to water?

Selected amphibian type

European fire-bellied toad (Bombina bombina), a member of the family Bombinatoridae

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.

In popular culture (folk taxonomy), toads are associated with drier, rougher skin and more terrestrial habitats. However, this distinction does not align precisely with scientific taxonomy. (Full article...)

List of selected amphibian type articles
Frog Salamander Caecilian

Selected images

Image 1
Atelopus limosus
Photograph: Brian Gratwicke
A female limosa harlequin frog (Atelopus limosus) in Panama. This endangered species of toad in the family Bufonidae inhabits stream banks in tropical moist lowland forests and rivers of the Chagres watershed. It is found in two colour forms, one in lowlands and one in uplands.
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Image 2
Balearic green toad
Photograph: Richard Bartz
A female Balearic green toad (Bufo balearicus), a lowland species of toad native to Italy.
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Image 3
New England Tree Frog
Photo credit: LiquidGhoul
The New England Tree Frog (Litoria subglandulosa) is a species of frog native to the streams of the New England Tablelands, New South Wales, Australia.
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Image 4
Eastern newt
Photo credit: Patrick Coin
A 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.
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Image 5
Golden toad
Photo: Charles H. Smith, USFWS
The golden toad (Bufo periglenes) is an extinct species of true toad that was once abundant in a small region of high-altitude cloud-covered tropical forests, about 30 km² (12 sq mi) in area, above the city of Monteverde, Costa Rica. The last reported sighting of a golden toad was on 15 May 1989. Its sudden extinction may have been caused by chytrid fungus and extensive habitat loss.
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Image 6
Rana clamitans
Photo credit: Derek Ramsey
The American Green Frog (Rana clamitans) is native to the eastern half of the United States and Canada. Green frogs live wherever there is shallow freshwater: ponds, road-side ditches, lakes, swamps, streams and brooks. The green frog is abundant wherever it occurs.
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Image 7
Emerald-eyed tree frog
Photo: Paolo Costa Baldi
The emerald-eyed tree frog (Rana platanera) is a species of frog in the family Hylidae found in South America.
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Image 8
Fire salamander
Photo: Archaeodontosaurus
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.
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Image 9
White-lipped tree frog
Photo: JJ Harrison
The white-lipped tree frog (Litoria infrafrenata) is the world's largest tree frog. This species is native to the rainforests of Northern Queensland, New Guinea, the Bismarck Islands and the Admiralty Islands. It can reach a length of over 13 cm (5 in), with females growing larger than males. The lower lip has a distinctive white stripe, giving this species its common name.
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Image 10
Phantasmal poison frog
Photograph: H. Krisp
The phantasmal poison frog (Epipedobates tricolor) is a species of poison dart frog endemic to Ecuador. First described by George Albert Boulenger in 1899, this endangered species is found only in rainforests on the slopes of the Andes.
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Image 11
Albanian water frog
Photograph: Benny Trapp
The 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.
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Image 12
American Toad
Photo: Simon Pierre Barrette
The Eastern American Toad (Bufo americanus americanus) is a common subspecies of toad found throughout the eastern United States and Canada. It typically grows to 5–9 cm (2.0–3.5 in), with varying skin color and pattern depending on its environment. Its skin secretes bufotoxin, which is mildly poisonous to humans.
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Image 13
Marsh frog
Photo: Marie-Lan Nguyen
The marsh frog (Pelophylax ridibundus) is a species of true frog and the largest frog native to Europe; females of this sexually dimorphic species may be up to 17 centimetres (6.7 in) long. The marsh frog feeds mainly on insects, but it also eats smaller amphibians, fish, and rodents.
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Image 14
Southern brown tree frog
Photograph: JJ Harrison
The southern brown tree frog (Litoria ewingii) is a species of tree frog native to Australia found in a wide range of habitats. Reaching 45 millimetres (1.8 in), this species is generally brown, but green and green-striped morphs are also recorded.
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Image 15
Raorchestes parvulus
Photograph credit: Rushenb
Raorchestes 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.
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Selected toad article

The Malabar tree toad (Pedostibes tuberculosus), or warty Asian tree toad, is a species of toad found in forests along the Western Ghats of great Karnataka or Deccan. It is a small species and is found in wet tree hollows or leaf bases containing water. It is the only species in the monotypic genus Pedostibes, also known as Asian tree toads. (Full article...)

List of selected toad articles

Selected caecilian article

Epicrionops sp.

Rhinatrematidae is a family of caecilians, also known as the Neotropical tailed caecilians, American tailed caecilians. or beaked caecilians. They are found in the equatorial countries of South America.

They are usually regarded as the most basal of the caecilian families, with numerous characteristics lacking in the other groups. For example, they still possess tails, and their mouths are not recessed on the underside of their heads. They lay their eggs in cavities in the soil. The larvae have external gills, and live in seepage areas until they metamorphose. The adults live in moist soil and leaf litter. (Full article...)

List of selected caecilian articles