Atelopus is a large genus of Bufonidae, commonly known as harlequin frogs or 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.
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, likely because the IUCN last assessed it in 2004. 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.
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.
Atelopus bomolochos, the Azuay stubfoot toad or Cuenca jambato frog, is a species of toad in the family Bufonidae. It is endemic to southern Ecuador and known from Cordillera Oriental in the Azuay, Cañar, and Loja Provinces.
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 exiguus is a species of toad in the family Bufonidae. It is endemic to Ecuador and only known from the area of its type locality in the Azuay Province of southern Ecuador, in the sub-páramo and páramo of Cordillera Occidental. Common name Mazán jambato frog has been proposed for it.
Atelopus ignescens, the Jambato toad or Quito stubfoot toad, is a species of toad in the family Bufonidae. It is endemic to the northern Andes of Ecuador. This once abundant species was believed to be extinct until its rediscovery in 2016. The specific name ignescens means "to catch fire", presumably in reference to the orange ventral color of this species.
Atelopus pachydermus is a species of toad in the family Bufonidae. It is found in the Andes of northern Peru and southern Ecuador. Records from Colombia reflect the vagueness of the stated type locality, "Neu-Granada", encompassing territory part of several present-day countries. Other records outside the current range refer to other species. The most recent record of this very rare and possibly extinct species is from around 1995. However, there is a need to reassess the status of this species because of confusion with Atelopus podocarpus.
Atelopus palmatus is a species of toad in the family Bufonidae. It is endemic to the Cordillera Oriental of eastern Ecuador and is known from the Napo and Pastaza Provinces at elevations of 1,150–1,740 m (3,770–5,710 ft) above sea level. Its type locality is "Rio Pastaza".
Atelopus planispina is a species of toad in the family Bufonidae. It is endemic to the eastern slopes of the Andes of Ecuador. According to the IUCN SSC Amphibian Specialist Group, it is restricted to the Napo Province, although other sources suggest somewhat wider range. It has not been seen since 1985 and might already be extinct. Common names Planispina's harlequin frog, Napo stubfoot toad, and flat-spined atelopus have been coined for it.
Atelopus vogli is an extinct species of harlequin frog in the family Bufonidae. It was endemic to Venezuela. It is known from collections in two localities: its type locality, Las Peñas near Hacienda la Trinidad in Aragua, and Montalbán in Carabobo. It was first described as subspecies of Atelopus cruciger. The specific name vogli honours Cornelius Vogl, German priest who was a missionary in Venezuela in 1925–1959. Common name Vogl's harlequin toad has been coined for it.
Melanophryniscus spectabilis is a species of toads in the family Bufonidae. It is known from western Santa Catarina and southern Paraná states, southern Brazil. The specific name spectabilis refers to the showy color pattern of this species.
Atelopus petersi is a species of toads in the family Bufonidae. It is endemic to Ecuador and is known from the Cordillera Oriental in the Napo Province and more provisionally, in the Chimborazo Province. The specific name petersi honors James A. Peters, an American zoologist who collected the first specimens of this species in 1962 and provided a description under the name Atelopus pachydermus. Common names Peters' stubfoot toad and Peters' jambato toad have been coined for it.
María Cristina Ardila-Robayo was a Colombian herpetologist. She was professor at the National University of Colombia, Bogotá, and worked closely with the Natural History Museum of the university. In 2010 she was credited as having described 28 new species of amphibians from Colombia; as of late 2018, the Amphibian Species of the World lists 31 valid species described by her. She also worked with caimans and crocodiles and lead biodiversity restoration projects.
Atelopus ardila is a species of frog in the family Bufonidae. It has not been seen since 1992, and is believed to be possibly extinct.
Atelopus pastuso is a species of frog in the family Bufonidae. It has not been seen since 1993, and is possibly extinct.
Atelopus podocarpus is a species of frog in the family Bufonidae. It has not been seen since 1994, and is believed to be possibly extinct.
Atelopus gigas is a species of frog in the family Bufonidae. It has not been seen since 1970 and is considered possibly extinct.
Atelopus orcesi is a species of frog in the family Bufonidae. It has not been seen since 1988, and is believed to be possibly extinct.
