Portal:Amphibians

The Amphibian Portal

Left to Right: Leaf green tree frog, Seymouria, Eastern newt, Mexican burrowing caecilian
Many amphibians—like this Ceratophrys cranwelli—exhibit biofluorescence.

Amphibians are four-limbed and ectothermic vertebrates of the class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial, fossorial, arboreal or freshwater aquatic ecosystems. Thus amphibians typically start out as larvae living in water, but some species have developed behavioural adaptations to bypass this.

The young generally undergo metamorphosis from larva with gills to an adult air-breathing form with lungs. Amphibians use their skin as a secondary respiratory surface and some small terrestrial salamanders and frogs lack lungs and rely entirely on their skin. They are superficially similar to reptiles like lizards but, along with mammals and birds, reptiles are amniotes and do not require water bodies in which to breed. With their complex reproductive needs and permeable skins, amphibians are often ecological indicators; 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 sarcopterygian fish with lungs and bony-limbed fins, features that were helpful in adapting to dry land. They diversified and became dominant during the Carboniferous and Permian periods, but were later displaced by reptiles and other vertebrates. The origin of modern amphibians belonging to Lissamphibia, which first appeared during the Early Triassic, around 250 million years ago, has long been contentious. However the emerging consensus is that they likely originated from temnospondyls, the most diverse group of prehistoric amphibians, during the Permian period. (Full article...)

Selected frog article

Pelobates cultripes

The Pelobatoidea are a superfamily of frogs. They typically combine a toad-like body shape with a frog-like, pointed face (hence the German name 'Krötenfrösche', literally 'toad frogs'). Phylogenetically they stand between primitive frogs (fire-bellied toads, midwife toads) on the one side and higher frogs (the family of true toads, tree frogs, and the family of true frogs) on the other and are therefore – among other things by characteristics of bone construction – in the suborder Mesobatrachia.

Per 2016, the Pelobatoidea contain 202 species in 11 genera and 2 families. The distribution covers Europe, North Africa and West Asia (Family Pelobatidae) and Southeast Asia (family Megophryidae). Their sister group are the Pelodytoidea, consisting of North American spadefood toads and parsley frogs.

A striking characteristic is the vertically slit pupil in daylight. The tongue is thick, circular, and almost entirely adhering to the floor of the mouth. When mating the males clutches the females in the lumbar region, just before the hind legs (inguinal Amplexus). (Full article...)
List of selected frog articles

Selected salamander article

Alpine salamander (Salamandra atra)

The Salamandroidea are a suborder of salamanders, referred to as advanced salamanders. The members of the suborder are found worldwide except for Antarctica, sub-Saharan Africa, and Oceania. They differ from suborder Cryptobranchoidea as the angular and prearticular bones in their lower jaws are fused, their trunk ribs are bicapitate, and all members use internal fertilization. The female is fertilized by means of a spermatophore, a sperm-containing cap placed by the male in her cloaca. The sperm is stored in spermathecae on the roof of the cloaca until it is needed at the time of oviposition.

The earliest known salamandroid fossils remain contested. Some studies suggest that the earliest salamandroids are represented byspecimens of the species Beiyanerpeton jianpingensis and Qinglongtriton gangouensis from the Tiaojishan Formation of Inner Mongolia, China, dated to the Late Jurassic about 157 million years ago. Alternative analyses suggest that Beiyanerpeton jianpingensis and Qinglongtriton gangouensis are stem salamanders and that the oldest known certain salamandroid is Valdotriton gracilis from the Early Cretaceous of Spain, about 127 Ma. (Full article...)

Did you know? –

Restoration of Gerobatrachus
Restoration of Gerobatrachus

Selected amphibian type

Spotted salamander, Ambystoma maculatum

Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten extant salamander families are grouped together under the order Urodela from the group Caudata. Salamander diversity is highest in eastern North America, especially in the Appalachian Mountains; most species are found in the Holarctic realm, with some species present in the Neotropical realm.

Salamanders rarely have more than four toes on their front legs and five on their rear legs, but some species have fewer digits and others lack hind limbs. Their permeable skin usually makes them reliant on habitats in or near water or other cool, damp places. Some salamander species are fully aquatic throughout their lives, some take to the water intermittently, and others are entirely terrestrial as adults.

This group of amphibians is capable of regenerating lost limbs as well as other damaged parts of their bodies. Researchers hope to reverse engineer the regenerative processes for potential human medical applications, such as brain and spinal cord injury treatment or preventing harmful scarring during heart surgery recovery. (Full article...)
List of selected amphibian type articles

Selected images

  • Image 1Southern brown tree frogPhotograph: JJ HarrisonThe 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.More selected pictures
    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.
  • Image 2Dendrobates azureusPhoto: 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.More selected pictures
    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.
  • Image 3Atelopus certusPhoto: Brian GratwickeAtelopus certus is a species of toad endemic to the Darién Province of eastern Panama. Much of its range falls within the Darién National Park, a protected area and World Heritage Site. It is classified as endangered, primarily due to the advancing wave of chytridiomycosis moving through Central America.More selected pictures
    Photo: Brian Gratwicke
    Atelopus certus is a species of toad endemic to the Darién Province of eastern Panama. Much of its range falls within the Darién National Park, a protected area and World Heritage Site. It is classified as endangered, primarily due to the advancing wave of chytridiomycosis moving through Central America.
  • Image 4Red-eyed Tree FrogPhoto credit: Carey James BalboaThe 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
    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.
  • Image 5Ecnomiohyla rabborumPhotograph: Brian GratwickeRabbs' fringe-limbed treefrog (Ecnomiohyla rabborum) is a large species of frog originally found in the forest canopies of central Panama. Only discovered in 2005, the species is thought to be extinct in the wild; only one specimen, a male at the Atlanta Botanical Garden, survives.More selected pictures
    Photograph: Brian Gratwicke
    Rabbs' fringe-limbed treefrog (Ecnomiohyla rabborum) is a large species of frog originally found in the forest canopies of central Panama. Only discovered in 2005, the species is thought to be extinct in the wild; only one specimen, a male at the Atlanta Botanical Garden, survives.
  • Image 6Agile frogPhotograph credit: Petar MiloševićThe 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
    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.
  • Image 7FrogspawnPhoto credit: TarquinIn 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
    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.
  • Image 8Common frogPhoto: 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.More selected pictures
    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.
  • Image 9Iberian midwife toadPhotograph: 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".More selected pictures
    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".
  • Image 10Common toads in amplexusPhoto: Bernie KohlTwo 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.More selected pictures
    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.
  • Image 11White's Tree FrogPhoto credit: liquidGhoulNative to Australia, White's Tree Frog grows up to 10 centimetres in length and is a popular household pet. In captivity, they have an average lifespan of 16 years. Its skin secretions contain caerins, a group of peptides with antibacterial and antiviral properties. Other peptides have been found to destroy HIV without harming healthy T-cells.More selected pictures
    Photo credit: liquidGhoul
    Native to Australia, White's Tree Frog grows up to 10 centimetres in length and is a popular household pet. In captivity, they have an average lifespan of 16 years. Its skin secretions contain caerins, a group of peptides with antibacterial and antiviral properties. Other peptides have been found to destroy HIV without harming healthy T-cells.
  • Image 12Raorchestes parvulusPhotograph 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.More selected pictures
    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.
  • Image 13Phantasmal poison frogPhotograph: H. KrispThe 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
    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.
  • Image 14Rana clamitansPhoto credit: Derek RamseyThe 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.More selected pictures
    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.
  • Image 15Golden toadPhoto: Charles H. Smith, USFWSThe 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.More selected pictures
    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.

Selected toad article

Rhinella diptycha, sometimes referred to as Cope's toad, Schneider's toad, cururu toad, or rococo toad, is a toad found in northern Argentina, Paraguay, Uruguay, eastern Bolivia, and eastern and southern Brazil. It is one of three rather similar species sometimes referred to as "cururu toads" in Brazil, the others being R. jimi and R. marina (cane toad). Like those, R. diptycha is a large toad, females up to 25 cm (9.8 in) in snout–to–vent length and males up to 18 cm (7.1 in).

Rhinella diptycha is a widespread and very common species that occurs in a variety of habitats but most commonly in open and urban ones. It breeds in permanent and temporary ponds, preferring ones without much vegetation. Its natural habitats include dry savanna, freshwater marshes, and intermittent freshwater marshes. It is threatened by habitat loss. It is sometimes kept as a pet, but pet trade is not occurring at levels that would constitute a threat. (Full article...)
List of selected toad articles

Selected caecilian article

Scolecomorphus kirkii

The Scolecomorphidae (from Greek: σκώλεκώς skólekós, 'wormlike' and Greek: μορφή morphḗ, 'form') are a family of caecilians also known as tropical caecilians, buried-eyed caecilians, or African caecilians. They are found in Cameroon in West Africa, and Malawi and Tanzania in East Africa. Caecilians are legless amphibians which superficially resemble worms or snakes.

Scolecomorphids have only vestigial eyes, which are attached to the base of a pair of tentacles underneath the snout. Unlike other caecilians, they have only primary annuli; these are grooves running incompletely around the body, giving the animal a segmented appearance. All other caecilians have a complex pattern of grooves, with secondary or tertiary annuli present. Also uniquely amongst tetrapods, the scolecomorphids lack a stapes bone in the middle ear.

At least some species of scolecomorphids give birth to live young, retaining the eggs inside the females' bodies until they hatch into fully formed offspring, without the presence of a free-living larval stage. (Full article...)

Need help?

Do you have a question about Amphibians that you can't find the answer to?

Consider asking it at the Wikipedia reference desk.

Topics

Subcategories

Category puzzle
Category puzzle
Select [►] to view subcategories
Amphibians
Amphibians by location
Amphibian taxa by rank
Amphibians by year of formal description
Lists of amphibians
Amphibian anatomy
Amphibian common names
Amphibian diseases
Amphibian hormones
Amphibian organizations
Amphibian redirects
Cave amphibians
Amphibian conservation
Extinct amphibians
Frogs
Gymnophiona
Amphibians and humans
Amphibia hybrids
Parasites of amphibians
Salamanders
Amphibian stubs

Associated Wikimedia

The following Wikimedia Foundation sister projects provide more on this subject:

Discover Wikipedia using portals

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.