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. All extant (living) amphibians belong to the monophyletic subclass Lissamphibia, with three living orders: Anura, 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. Their life cycle typically starts out as aquatic larvae with gills known as tadpoles, but some species have developed behavioural adaptations to bypass this.
A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura. The oldest fossil "proto-frog" Triadobatrachus is known from the Early Triassic of Madagascar, but molecular clock dating suggests their split from other amphibians may extend further back to the Permian, 265 million years ago. Frogs are widely distributed, ranging from the tropics to subarctic regions, but the greatest concentration of species diversity is in tropical rainforest. Frogs account for around 88% of extant amphibian species. They are also one of the five most diverse vertebrate orders. Warty frog species tend to be called toads, but the distinction between frogs and toads is informal, not from taxonomy or evolutionary history.
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 tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found in adult amphibians such as a lateral line, gills and swimming tails. As they undergo metamorphosis, they start to develop functional lungs for breathing air, and the diet of tadpoles changes drastically.
The Alytidae are a family of primitive frogs. Their common name is painted frogs or midwife toads. Most are endemic to Europe, but three species occur in northwest Africa, and a species formerly thought to be extinct is found in Israel.
The common toad, European toad, or in Anglophone parts of Europe, simply the toad, is a frog found throughout most of Europe, in the western part of North Asia, and in a small portion of Northwest Africa. It is one of a group of closely related animals that are descended from a common ancestral line of toads and which form a species complex. The toad is an inconspicuous animal as it usually lies hidden during the day. It becomes active at dusk and spends the night hunting for the invertebrates on which it feeds. It moves with a slow, ungainly walk or short jumps, and has greyish-brown skin covered with wart-like lumps.
The common frog or grass frog, also known as the European common frog, European common brown frog, European grass frog, European Holarctic true frog, European pond frog or European brown frog, is a semi-aquatic amphibian of the family Ranidae, found throughout much of Europe as far north as Scandinavia and as far east as the Urals, except for most of the Iberian Peninsula, southern Italy, and the southern Balkans. The farthest west it can be found is Ireland. It is also found in Asia, and eastward to Japan. The nominative, and most common, subspecies Rana temporaria temporaria is a largely terrestrial frog native to Europe. It is distributed throughout northern Europe and can be found in Ireland, the Isle of Lewis and as far east as Japan.
The European fire-bellied toad is a species of fire-bellied toad native to eastern parts of mainland Europe, where it can be found near waterbodies such as ponds and marshes. It is known for its red colored belly used to ward off predators, an example of aposematism, and its distinctive "whoop" call.
The American toad is a common species of toad found throughout Canada and the eastern United States. It is divided into three subspecies: the eastern American toad, the dwarf American toad and the rare Hudson Bay toad. Recent taxonomic treatments place this species in the genus Anaxyrus instead of Bufo.
Gastrophryne carolinensis, the eastern narrow-mouthed toad, is a species of microhylid frog. It is a relatively small, toad-like amphibian found in damp, shady habitats. The species is highly fossorial, and feeds primarily on ants. These North American microhylids are distinguished from true toads, and other anurans by their moist, smooth skin, their lack of eardrums or tympana, their distinguishable squat body shape, and the unique fold of skin superior to their eyes. It is found in the United States, from southern Maryland to the Florida Keys, west to Missouri and Texas. While not a true toad, it is so called because it is terrestrial.
The Majorcan midwife toad is a frog in the family Alytidae. It is endemic to the Balearic Island of Majorca in the Mediterranean Sea. An example of Lazarus taxon, the species was first described from fossil remains in 1977, but living animals were discovered in 1979.
The oak toad is a species of toad in the family Bufonidae. It is endemic to the coastal regions of southeastern United States. It is regarded as the smallest species of toad in North America, with a length of 19 to 33 mm.
The yellow-throated frog, Trinidadian stream frog, or Trinidad poison frog is a diurnal species of frog in the family Aromobatidae that is endemic to the island of Trinidad in the Republic of Trinidad and Tobago. Trinidad poison frogs can be found in rocky streams in moist montane forests. The species has cryptic coloration and is sexually dimorphic. Mannophryne venezuelensis from the Paria Peninsula in Venezuela were also formerly included in this species. Currently this species is listed as of "Least Concern" on IUCN, but there is a general lack of understanding of its distribution. The frog experiences habitat loss. Both sexes are territorial and provide parental care together.
The Iberian midwife toad or brown midwife toad, in Portuguese sapo-parteiro-ibérico, is a species of frog in the family Alytidae found in Portugal and western Spain. It is typically found in open habitats such as meadows and open oak forests. Habitat loss is one of the threats to its survival.
The Betic midwife toad or Sapo Partero Bético is a species of frog in the family Alytidae. It is endemic to mountainous in south eastern Spain. Its natural habitats are temperate forests, freshwater marshes, intermittent freshwater marshes, pastureland, ponds, and aquaculture ponds. It is threatened by habitat loss.
The common midwife toad is a species of midwife frog in the family Alytidae. It is found in Belgium, France, Germany, Luxembourg, the Netherlands, Portugal, Spain, Switzerland, and the United Kingdom. Like other members of its genus (Alytes), the male toad carries the eggs around entwined on his back and thighs until they are ready to hatch.
Discoglossus pictus, the Mediterranean painted frog or simply painted frog, is a species of frog in the family Alytidae.
The cane toad in Australia is regarded as an exemplary case of an invasive species. Australia's relative isolation prior to European colonisation and the Industrial Revolution, both of which dramatically increased traffic and import of novel species, allowed development of a complex, interdepending system of ecology, but one which provided no natural predators for many of the species subsequently introduced. The recent, sudden inundation of foreign species has led to severe breakdowns in Australian ecology, after overwhelming proliferation of a number of introduced species, for which the continent has no efficient natural predators or parasites, and which displace native species; in some cases, these species are physically destructive to habitat, as well. Cane toads have been very successful as an invasive species, having become established in more than 15 countries within the past 150 years. In the Environment Protection and Biodiversity Conservation Act 1999, the Australian government listed the impacts of the cane toad as a "key threatening process".
The common Surinam toad, the Suriname toad, or star-fingered toad, is a fully-aquatic species of frog, in the family Pipidae, with a widespread range across much of tropical South America and the island of Trinidad. The females of this species are well-known for "incubating" their eggs on their backs, in honeycomb-like depressions directly within the skin, releasing fully-formed froglets after a period of 4–5 months. Pipa pipa is an ambush predator, lying in-wait underwater for prey to inevitably wander too close, swiftly inhaling the unsuspecting creature using suction feeding. Additionally, the Surinam toad's rather flat body shape, combined with rather dark, dull coloration, serves as effective camouflage in the murky waters they inhabit, perfectly mimicking a dead leaf or piece of rotting wood as they await their next meal.
