Chytridiomycosis(chy·trid·i·o·my·co·sis | \ kī-ˌtri-dē-ō-mī-ˈkō-səs) is an infectious disease in amphibians, caused by the chytrid fungi Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans, a non-hyphal zoosporic fungus. Chytridiomycosis has been linked to dramatic population declines or extinctions of amphibian species in western North America, Central America, South America, eastern Australia, East Africa (Tanzania), and Dominica and Montserrat in the Caribbean. Much of the New World is also at risk of the disease arriving within the coming years. The fungus is capable of causing sporadic deaths in some amphibian populations and 100% mortality in others. No effective measure is known for control of the disease in wild populations. Various clinical signs are seen by individuals affected by the disease. A number of options are possible for controlling this disease-causing fungus, though none has proved to be feasible on a large scale. The disease has been proposed as a contributing factor to a global decline in amphibian populations that apparently has affected about 30% of the amphibian species of the world. Some research found evidence insufficient for linking chytrid fungi and chytridiomycosis to global amphibian declines, but more recent research establishes a connection and attributes the spread of the disease to its transmission through international trade routes into native ecosystems.
Atelopus is a large genus of true toads, commonly known as harlequin toads or stubfoot toads, from Central and South America, ranging as far north as Costa Rica and as far south as Bolivia. Atelopus species are small, generally brightly colored, and diurnal. Most species are associated with mid-to-high elevation streams. This genus has been greatly affected by amphibian declines, and many species are now considered endangered, while others already are extinct. Almost 40% of the described species in the genus are considered possibly extinct; this is raised to 45% when data deficient species are added; this number may be even higher, given that the genus contains many undescribed species that could also be extinct, and many of the species considered critically endangered but extant may have gone extinct after the last surveys that detected them, or could go extinct in the future. While threatened by habitat loss, pollution, and introduced species, the primary cause of these declines appears to be the chytrid fungus Batrachochytrium dendrobatidis. For example, there are 32 known Atelopus species in Ecuador. One of these is data deficient, two are endangered and the remaining are critically endangered. Almost half the Ecuador species have not been recorded in a decade or more and are likely extinct. In some species conservationists have established captive colonies as a safeguard. However, numerous Atelopus species have been rediscovered decades after their last sighting, such as A. arsyescue, A. mindoensis, A. bomolochos, A. ignescens, A. balios, A. longirostris, A. subornatus and A. varius.
Holdridge's toad is a species of toad endemic to Costa Rica. In October 2008, it was declared extinct by the International Union for Conservation of Nature in its Red List since the species had not been seen since 1987, despite years of extensive searches. However, the species was rediscovered in 2010 by a Costa Rican herpetologist and is now classified as critically endangered. It is believed that the species is most threatened by the presence of the chytrid fungus in its habitat.
Batrachochytrium dendrobatidis, also known as Bd or the amphibian chytrid fungus, is a fungus that causes the disease chytridiomycosis in amphibians.
Atelopus longirostris is a species of harlequin frog, a member of the family of true toads (Bufonidae). It has been recorded only in northern Ecuador. Records from Colombia probably represent different species. As of mid-2017, it is listed as extinct by the IUCN, but was rediscovered in 2016 after more than two decade with no sightings. The scientific name of this species means "long-snout" and the species has been named in Spanish as the jambato hocicudo. Common names longnose stubfoot toad, scrawny stubfoot-toad, and longnose sharlequin frog have been coined for it.
The Panamanian golden frog, also known as Cerro Campana stubfoot toad and other names, is a species of toad endemic to Panama. Panamanian golden frogs inhabit the streams along the mountainous slopes of the Cordilleran cloud forests of west-central Panama. While the IUCN lists it as critically endangered, it may in fact have been extinct in the wild since 2007. Individuals have been collected for breeding in captivity in a bid to preserve the species. The alternative common name, Zetek's golden frog, and the epithet zeteki both commemorate the entomologist James Zetek.
Atelopus varius, the Costa Rican variable harlequin toad or clown frog, is a small Neotropical true toad from the family Bufonidae. Once ranging from Costa Rica to Panama, A. varius is now listed as critically endangered and has been reduced to a single remnant population near Quepos, Costa Rica and has only relict populations in western Panama (IUCN). Recent variation in air temperature, precipitation, stream flow patterns, and the subsequent spread of a pathogenic chytrid fungus (Batrachochytrium dendrobatidis) linked to global climate change have been the leading cause of decline for A. varius. A. zeteki has been considered a subspecies of A. varius, but is now generally considered a separate species.
Atelopus balios, the Rio Pescado stubfoot toad, is a species of toad in the family Bufonidae. It is endemic to southwestern Ecuador, with records from Pacific lowlands in Azuay, Cañar, and Guayas Provinces. It is a rare species that was already suspected to be extinct, but a single specimen was discovered in 2011 by a team from Conservation International during a hunt for missing amphibians. The decline in amphibian populations is well documented. The Atelopus balios is Critically Endangered as a result of the widespread amphibian Chytridiomycosis fungus that has decimated other amphibian populations. There are only 10 known findings of the tadpole, Atelopus balios.
The Guajira stubfoot toad or Carrikeri harlequin frog, Atelopus carrikeri, is a species of toad in the family Bufonidae. It is about 5 cm (2.0 in) long and typically black, though some populations have orange coloration. This species is endemic to the Sierra Nevada de Santa Marta mountain range of northern Colombia. It is critically endangered because of the chytrid fungus, Batrachochytrium dendrobatidis, and habitat destruction due to agriculture. The species had not been seen from 1994 until it was rediscovered in early 2008.
Atelopus certus, the Darien stubfoot toad or Toad Mountain harlequin frog, is a species of toad in the family Bufonidae endemic to Panama.
Atelopus chiriquiensis, the Chiriqui harlequin frog or Lewis' stubfoot toad, is an extinct species of toad in the family Bufonidae that was found in the Cordillera de Talamanca in Costa Rica and western Panama. Its natural habitats were stream margins in lower montane wet forests and rainforests. Its elevational range was 1,400–2,500 m (4,600–8,200 ft) asl.
Atelopus cruciger, also known as the Veragua stubfoot toad or Rancho Grande harlequin frog, is a species of toad in the family Bufonidae. It is endemic to Venezuela and is known from the central Venezuelan Coastal Range. The species was already suspected to be extinct because, despite considerable effort, none had been found since 1986. However, in 2003, a small population was found, with few other locations discovered later. It is mainly threatened by chytridiomycosis. It is locally called sapito rayado.
Atelopus glyphus, the Pirri harlequin frog or Pirri Range stubfoot toad, is a species of toad in the family Bufonidae found in Colombia and Panama within the Northwestern Andean montane forests. Its natural habitats are subtropical or tropical moist montane forests and rivers.
Atelopus pulcher is a species of toad in the family Bufonidae. It is endemic to eastern Peru where it is found in the Huallaga River drainage; its range might extend to Ecuador. Its natural habitats are lowland and premontane tropical forests. It is a diurnal and terrestrial species that breeds in streams.
Agalychnis lemur, also known as the lemur leaf frog or lemur frog, is a species of frog in the family Phyllomedusidae, also treated as the subfamily Phyllomedusinae in the Hylidae. It is found in Costa Rica, Panama, and adjacent northwestern Colombia. It is classed as Critically Endangered and threatened by the fungal disease chytridiomycosis.
The La Loma tree frog is a species of frog in the family Hylidae found in Costa Rica, Panama, and expected but not confirmed in Colombia. Its natural habitats are tropical moist lowland and montane forests, with breeding taking place in streams. It is threatened by habitat loss and chytridiomycosis.
The horned marsupial frog, originally named Nototrema cornutum Boulenger after the first describer George Albert Boulenger in 1898), is a species of frog in the family Hemiphractidae. It is an arboreal species found in Colombia, Costa Rica, Ecuador and Panama. Its natural habitats are tropical moist lowland forests and montane cloud forests. It is threatened by habitat loss.
Hemiphractus fasciatus, or the banded horned treefrog, is a species of frog in the family Hemiphractidae. It is found in northwestern Ecuador and possibly the Pacific slopes of the Cordillera Occidental in Colombia; although formerly listed for Panama, this involves the similar and closely related H. elioti, H. kaylockae and H. panamensis. It is a relatively large frog that may readily bite.
The golden toad is an extinct species of true toad that was once abundant in a small, high-altitude region of about 4 square kilometres (1.5 sq mi) in an area north of the city of Monteverde, Costa Rica. It was endemic to elfin cloud forest. Also called the Monte Verde toad, Alajuela toad and orange toad, it is commonly considered the "poster child" for the amphibian decline crisis. This toad was first described in 1966 by herpetologist Jay Savage. The last sighting of a single male golden toad was on 15 May 1989, and it has since been classified as extinct by the International Union for Conservation of Nature (IUCN).
Atelopus patazensis is a species of toads in the family Bufonidae. It is endemic to Peru and only known from its type locality in Quebrada Los Alisos, near Pataz in the La Libertad Region. There is, however, an unverified observation from Llacuabamba, about 40 km south of Pataz.
