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 lepospondyls. A fourth group of lissamphibians, the Albanerpetontidae, became extinct around 2 million years ago. (Full article...)
Selected frog article
The Ceratobatrachidae are a family of frogs found in the Malay Peninsula, Borneo, the Philippines, Palau, Fiji, New Guinea, and the Admiralty, Bismarck, and Solomon Islands. (Full article...)
Selected salamander article
Ambystomatidae is a family of salamanders belonging to the Suborder Salamandroidea in the class Amphibia. It contains two genera, Ambystoma (the mole salamanders) and Dicamptodon (the Pacific giant salamanders). Ambystoma contains 32 species and are distributed widely across North America, while Dicamptodon contains four species restricted to the Pacific Northwest. These salamanders are mostly terrestrial and eat invertebrates, although some species are known to eat smaller salamanders. They can be found throughout the US and some areas of Canada in damp forests or plains. This family contains some of the largest terrestrial salamanders in the world, the tiger salamander and the coastal giant salamander. Some species are toxic and can secrete poison from their bodies as protection against predators or infraspecific competition. Neoteny has been observed in several species in Ambystomatidae, and some of them like the axolotl live all of their lives under water in their larval stage. (Full article...)
List of selected salamander articles
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Did you know? –
- ... that the Pyrenean brook salamander sometimes lives entirely underground in caves?
- ... that Rhachitomi, a group of temnospondyl amphibians, was established as a clade in 2013?
- ... that the specific name of Tambachia trogallas, the type species of the trematopid temnospondyl Tambachia, refers to the Thuringian bratwurst that was frequently eaten by the describers of the species?
- ... that the female tree frog Aplastodiscus leucopygius inspects the underground nesting chamber prepared by the male before accepting his advances?
- ... that the Italian pool frog (pictured) has been introduced into the United Kingdom?
Selected amphibian type
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 made in scientific taxonomy (see below). In popular culture (folk taxonomy), toads are associated with drier, rougher skin and more terrestrial habitats. (Full article...)
List of selected amphibian type articles
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Selected images
Selected toad article
The Korean water toad, Korean toad, water toad, or Stejneger's toad (Bufo stejnegeri), is a species of toad found in East Asia. Two distinct populations are known to exist, one in eastern Liaoning province of northeastern China, and one in the central mountains of the Korean Peninsula. Within South Korea, it is found in eastern Gyeonggi (specifically Gapyeong) and also in Gangwon-do (particularly the Odaesan mountain complex). In addition, it is expected that there are or have been additional populations in the region between central Korea and Liaoning.
The classification of the Korean water toad into the genus Bufo was challenged in a 2006 paper. However, no alternative classification was proposed and the species is at present provisionally allocated to Bufo.
The Korean water toad is found inland, at elevations from 200 to 700 meters above sea level. As its name suggests, it favors water, and is typically found in wooded riparian areas. Breeding and egg-laying take place in the waters of streams and rivers. The water toad is typically nocturnal, but is also active during the day during the summer rains. (Full article...)
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...)
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