Portal:Amphibians

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, but 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 even 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...)

Refresh with new selections below (purge)

Selected frog article

Leptodactylus albilabris

The southern frogs form the Leptodactylidae, a name that comes from Greek meaning a bird or other animal having slender toes. They are a diverse family of frogs that most likely diverged from other hyloids during the Cretaceous. The family has undergone major taxonomic revisions in recent years, including the reclassification of the former subfamily Eleutherodactylinae into its own family the Eleutherodactylidae; the Leptodactylidae now number 206 species in 13 genera distributed throughout Mexico, the Caribbean, and Central and South America. The family includes terrestrial, burrowing, aquatic, and arboreal members, inhabiting a wide range of habitats.

Several of the genera within the Leptodactylidae lay their eggs in foam nests. These can be in crevices, on the surface of water, or on forest floors. These foam nests are some of the most varied among frogs. When eggs hatch in nests on the forest floor, the tadpoles remain within the nest, without eating, until metamorphosis. (Full article...)

List of selected frog articles

Selected salamander article

The greater siren (Siren lacertina) is an amphibian and one of the five members of the genus Siren. The largest of the sirens and one of the largest amphibians in North America, the greater siren resides in the coastal plains of the southeastern United States. (Full article...)

List of selected salamander articles
Caudata Ambystomatidae Cryptobranchoidea Salamanders in folklore Salamandroidea Sexual selection in amphibians Sirenidae Urodela

Did you know? – show different entries

...that the extinct crocodile-like Prionosuchus (scale image pictured) is the largest amphibian known to have existed?
... that the Iberian frog includes beetles, caddisflies and spiders in its diet?
...that the California slender salamander (pictured) has a physique to invade narrow tunnels of earthworms for predation and cover?
... that Wilmer W. Tanner wrote his Ph.D. thesis on the comparative anatomy of salamanders from Mexico and Central America?
... that the new genus of frog Mercurana was named after the late British rock singer Freddie Mercury?

Selected amphibian type

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

Toad (also known as a hoptoad) 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 distinguished from frogs by their drier, rougher skin and association with 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
Epirus water frog
Photograph: Benny Trapp
The Epirus water frog (Pelophylax epeiroticus) is a species of frog in the family Ranidae. It is found in western Greece, including Corfu, and the southern areas of Albania. The species is collected from the wild for human consumption.
More selected pictures
Image 2
Marsh frog
Photograph credit: Charles James Sharp
The 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.
More selected pictures
Image 3
Balearic green toad
Photograph: Richard Bartz
A female Balearic green toad (Bufo balearicus), a lowland species of toad native to Italy.
More selected pictures
Image 4
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.
More selected pictures
Image 5
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.
More selected pictures
Image 6
Leaf Green Tree Frog
Photo credit: Froggydarb
A specimen from the "hybrid zone" of the Leaf Green Tree Frog (Litoria phyllochroa) and the Southern Leaf Green Tree Frog (L. nudidigitus), showing physical characteristics of both species. These small stream-dwelling frogs (averaging only 40mm in length), are native to eastern Australia and occur together south of Sydney. The two species are differentiated only by distribution, call and slight differences in flank markings.
More selected pictures
Image 7
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.
More selected pictures
Image 8
Iberian midwife toad
Photograph: Benny Trapp
The 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".
More selected pictures
Image 9
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.
More selected pictures
Image 10
Red-eyed Tree Frog
Photo credit: Carey James Balboa
The Red-eyed Tree Frog (Agalychnis callidryas) is a small-sized tree frog, reaching lengths of about 5 to 7 centimeters (3 inches), native to Neotropical rainforests in Central America. They are not poisonous and rely on camouflage to protect them. During the day, they remain motionless with their colorful parts hidden. Thus, they appear almost completely green, and well hidden among the foliage.
More selected pictures
Image 11
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.
More selected pictures
Image 12
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.
More selected pictures
Image 13
Frogspawn
Photo credit: Tarquin
In the life cycle of a frog, a female lays her eggs in a shallow pond or creek, where they will be sheltered from the current and from predators. The eggs, known as frogspawn hatch into tadpoles. The tadpoles develop gradually into adolescent froglets and finally the froglet develops into an adult frog.
More selected pictures
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.
More selected pictures
Image 15
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.
More selected pictures

Selected toad article

A Kihansi spray toad at Bronx Zoo

The Kihansi spray toad (Nectophrynoides asperginis) is a small toad endemic to Tanzania. The species is live-bearing and insectivorous. The Kihansi spray toad is currently categorized as Extinct in the Wild by the International Union for Conservation of Nature (IUCN), though the species persists in ex situ, captive breeding populations. Currently, there are an estimate of 6,200 Kihansi spray toads in captivity, mainly in Bronx Zoo and Toledo Zoo. (Full article...)

List of selected toad articles

Selected caecilian article

The Grandisoniidae are a family of common caecilians found in Africa, Seychelles and India. Like other caecilians, they superficially resemble worms or snakes. The family was formerly known as Indotyphlidae. (Full article...)

List of selected caecilian articles