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

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Selected frog article

Odontophrynus cultripes

The Odontophrynidae are a family of frogs from southern and eastern South America. This family was first established in 1969 as the tribe Odontophrynini within the (then) very large family Leptodactylidae. Molecular phylogenetics analyses prompted the move of this group to the Cycloramphidae in 2006, before they became recognized as their own family Odontophrynidae in 2011. (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 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

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.

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
Frog Salamander Caecilian

Selected images

Image 1
Edible frog
Photograph: Grand-Duc; edit: Niabot
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.
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Image 2
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 3
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 4
Vocal sac
Photo: Benny Trapp
An 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.
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Image 5
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 6
Common frog
Photo: Richard Bartz
The 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.
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Image 7
Red-eyed Tree Frog
Photo credit: LiquidGhoul
The 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.
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Image 8
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 9
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 10
Common Indian Toad
Photo: Lokionly
The Common Indian Toad (Duttaphrynus melanostictus) is native to South Asia. It grows to about 20 cm (8 in) long and breeds during monsoon season. These toads are often seen at night under street lamps especially during times when winged termites swarm. They have been noted to feed on a wide range of invertebrates, including scorpions.
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Image 11
Panamanian golden frog
Photograph: Brian Gratwicke
The Panamanian golden frog (Atelopus zeteki) is a rare species of toad endemic to Panama. First described by Emmett Reid Dunn in 1933, this species was found close to mountain streams on the eastern side of the Tabasará mountain range in Coclé and Panamá Provinces, but is now critically endangered and possibly extinct in the wild.
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Image 12
White's Tree Frog
Illustration credit: Ernst Haeckel
A frog is an amphibian characterized by long hind legs, a short body, webbed digits, protruding eyes and the absence of a tail. Frogs are most noticeable through their call, which can be widely heard during the mating season. It is estimated that up to 20% of amphibian species may care for their young in one way or another, and there is a great diversity of parental behaviours. For example, frogs in the Gastrotheca genus (upper left) carry their eggs in a pouch, and females of the Eleutherodactylus lineatus species (center left) carry their young on their back.
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Image 13
Dendrobates azureus
Photo: Quartl
Dendrobates 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.
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Image 14
Agile frog
Photograph credit: Petar Milošević
The agile frog (Rana dalmatina) is a species of true frog in the family Ranidae. Native to central and southern Europe, its brownish dappled colouring helps to conceal it among the leaf litter on the forest floor. This frog, about 5 cm (2.0 in) long, was photographed in the Golovec Forest in Slovenia.
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Image 15
Common toads in amplexus
Photo: Bernie Kohl
Two common toads (Bufo bufo) in amplexus, a form of pseudocopulation found in amphibians and limulids. A male common toad grasps a female with his front legs as part of the mating process. Common toads stay in amplexus for several days. As the female lays a long, double string of small black eggs, the male fertilises them with his sperm; the gelatinous egg strings, which may contain 3000 to 6000 eggs and be 3 to 4.5 metres (10 to 15 ft) in length, are later tangled in plant stalks.
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Selected toad article

Cane toad (Rhinella marina)

Rhinella, commonly known as South American toads, beaked toads or Rio Viejo toads, is a genus of true toads native to Neotropical parts of Mexico, Central and South America. Additionally, the cane toad has been Introduced to Australia, the Caribbean, the Philippines and elsewhere.

Originally, all species of the genus Rhinella were included in the genus Bufo, then they were split into the genera Chaunus and Rhamphophryne. However, Chaunus and Rhamphophryne are now considered synonyms of Rhinella. (Full article...)

List of selected toad articles

Selected caecilian article

Schistometopum thomense

Schistometopum is a genus of amphibian in the family Dermophiidae. S. thomense is only known from two islands in the Bight of Benin, but has been reported from "Upper Zaïre". This likely refers to an undiscovered third species. (Full article...)

List of selected caecilian articles