AmphibiaWeb - Atelopus loettersi


(Translations may not be accurate.)

Atelopus loettersi De la Riva, Castroviejo-Fisher, Chaparro, Boistel & Padial, 2011
family: Bufonidae
genus: Atelopus
Species Description: de la Riva I, Castroviejo-Fisher S, Chapparo JC, Boistel R, Padial JM 2011 A new species of Atelopus (Anura: Bufonidae) from the Amazonian slopes of the Andes in south-eastern Peru. Salamandra 47:161-168.
Conservation Status (definitions)
IUCN Red List Status Account Near Threatened (NT)
National Status None
Regional Status None



View distribution map in BerkeleyMapper.


Atelopus loettersi is harlequin toad described from one female, two males, and two juveniles. The female had a snout-vent length of 35.2mm, while males were smaller, ranging from 24.7 and 26.7 mm, respectively. The skin of A. loettersi is covered by coni, which are miniature pointed spicules. The snout is pointy with a rounded tip. Atelopus loettersi has long hind limbs and a foot that is longer than its tibia (De la Riva et al. 2011).

Atelopus loettersi is morphologically similar to A. pulcher and A. spumarius, where color and pattern alone cannot be used to distinguish between them. However, both A. pulcher and A. spumarius have a smooth dorsal skin whereas A. loettersi has a skin covered by coni. Additionally, while A. pulcher has a similar snout-vent-length (female, 34.1 ± 1.12mm), whereas A. spumarius has on average a shorter snout-vent-length (female, 25.2 ± 1.94 mm) than A. loettersi. In addition, A. loettersi lacks a middle ear, which is present in A. pulcher; this feature is yet unknown in A. spumarius (De la Riva et al. 2011, Lotters et al. 2002).

In life, the dorsal coloration of A. loettersi is dark brown with defined, irregular bright green markings. For females, the majority of the ventral surface is covered in a bright red color, with creamy white or yellow color around the neck area. While for males, the ventral surface of males is mostly covered in creamy, yellow or white color with front and back palms as well as their connection to the lower thigh colored in bright red (De la Riva et al. 2011).

There is very mild variation that may be sexually dimorphic. The lone female had a head that was longer than wide and an eye diameter what was smaller then the eye-nostril distance. Additionally, in life the coloration of the female differs from males (see above). Females have a paler dorsum, more extensive red colouration on belly, throat and chest, and a yellow venter with irregular grey blotches (De la Riva et al. 2011).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Peru


View distribution map in BerkeleyMapper.

Atelopus loettersi is distributed along the piedmont of the Cordillera Oriental (the eastern Andes) in southeastern Peru, likely extending across parts of the regions of Puno, Cusco and Madre de Dios (De la Riva et al. 2011). They are also expected to occur near the Bolivian border, in Madidi National Park as well as near the headwaters of the Madre de Dios river basin drainage system (IUCN 2020).

The elevational range of this species is between 400 - 1080 meters above sea level (IUCN 2020).

Atelopus loettersi generally inhabits terrestrial freshwater habitat in lowland, wetland and inland tropical rainforests (De la Riva et al. 2011).

Life History, Abundance, Activity, and Special Behaviors

The holotype for this species was found at night, sitting off the ground on a plant near a 3-meter-wide creek with clear water. There were no signs of human perturbation, and a rich invertebrate fauna (De la Riva et al. 2011).

Vocalizations of frogs of the genus Atelopus include three discrete types of signals: pulsed calls, pure tone calls, and short calls (Cocroft et al. 1990). The behavior of this particular species has not been recorded.

This species is rarely encountered. The population of this species is fragmented into groups at different locations, and it can be locally abundant (IUCN 2020).

Trends and Threats

The overall population trend of A. loettersi has been declining and is expected to decline overtime. Atelopus loettersi is mainly threatened by habitat loss and degradation from human perturbation. Activities including gold mining, illegal logging, and road construction have been known to lead to pollution as well as direct destruction of the species’ local habitat (IUCN 2020).

The genus Atelopus is among one of the most threatened vertebrate groups. Chytridiomycosis, an amphibian fungal disease, is recognised as an important driver of their population decline (Scheele et al., 2019, La Marca et al. 2005, Stuart et al. 2008). The impact of chytridiomycosis on A. loettersi particularly is unknown to date. However, chytrid likely threatens A. loettersi populations living more than 1000 meters above sea level, and is less likely to threaten lowland populations (IUCN 2020).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities


Using genetic data from a fragment of the 16S rRNA gene in PhyML, A. loettersi was found to be most closely related to two other Atelopus species ranging along the Peruvian-Bolivian border: A. oxapampae and A. tricolor. These three species all lack middle ears and are clearly in their own clade, apart from other Amazonian-Guianan Atelopus species (Lotters et al. 2011).

This information is supported by an article that conducted phylogenetic analysis based on 16S rRNA and COI with PhyML, concluding that the clade composed of A. tricolor and A. oxapampae is the closest related clade to A. loettersi (Jorge et al. 2020 Diversity). However, a phylogenetic tree in an article later published by the same author presented different information. It indicated that the clade composed of A. bomolochos, A. peruensis and A. spurrelli is sister to A. loettersi (Jorge et al. 2020 Journal). However, as A. oxapampae and A. tricolor were not included in the scope of analysis for this article, this tree topology as a whole does not conflict with previous data.

Although their appearance is largely similar, A. loettersi and A. pulcher were found to belong to different major clades within the harlequin frogs (De la Riva et al. 2011). Data from the other morphologically similar species, A. spumarius, is lacking.

The scientific name, A. loettersi, honors Professor Stefan Lötters at Trier University, Germany. This species was named in recognition of his continuous contributions towards the taxonomy, systematics, and conservation of harlequin frogs.


Cocroft, R. B., McDiarmid, R. W. , Jaslow, A. P., and Ruiz-Carranza, P. M. (1990). "Vocalizations of Eight Species of Atelopus (Anura: Bufonidae) with Comments on Communication in the Genus." Copeia, 3, 631-643. [link]

De la Riva, I., Castroviejo-Fisher, S., Chaparro, J. C., Boistel, R., Padial, J. (2011). "A new species of Atelopus (Anura: Bufonidae) from the Amazonian slopes of the Andes in south-eastern Peru." Salamandra, 47, 161-168.

IUCN SSC Amphibian Specialist Group. (2020). "Atelopus loettersi (amended version of 2017 assessment)." The IUCN Red List of Threatened Species 2020: e.T21567301A176048029. Accessed on 01 February 2022.

Jorge R.F., Ferrão, M., and Lima, A.P. (2020). "Out of Bound: A New Threatened Harlequin Toad (Bufonidae, Atelopus) from the Outer Borders of the Guiana Shield in Central Amazonia Described through Integrative Taxonomy." Diversity, 12(8), 310. [link]

Jorge, R.F., Magnusson, W.E., Silva, D.A., Polo, É.M., and Lima, A.P. (2020). "Urban growth threatens the lowland Amazonian Manaus harlequin frog which represents an evolutionarily significant unit within the genus Atelopus (Amphibia: Anura: Bufonidae)." Journal of Zoological Systematics and Evolutionary Research, 58, 1195-1205. [link]

La Marca, E., Lips, K. R., Lötters, S., Puschendorf, R., Ibáñez, R., Rueda-Almonacid, J. V., Schulte, R., Marty, C., Castro, F., Manzanilla-Puppo, J., García-Pérez, J. E., Bolaños, F., Chaves, G., Pounds, J. A., Toral, E., and Young, B. E. (2005). "Catastrophic population declines and extinctions in Neotropical harlequin frogs (Bufonidae: Atelopus)." Biotropica, 37, 190–201.

Lötters, S., Haas, W., Schick, S., and Böhme, W. (2002). "On the systematics of the harlequin frogs (Amphibia: Bufonidae: Atelopus) from Amazonia. II. Redescription of Atelopus pulcher (Boulenger, 1882) from the eastern Andean versant in Peru." Salamandra, 38, 165–184.

Lötters, S., Van der Meijden, A., Coloma, L. A., Boistel, R., Cloetens, P., Ernst, R., Lehr, E. & Veith, M. (2011). "Assessing the molecular phylogeny of a near extinct group of vertebrates: the Neotropical harlequin frogs (Bufonidae; Atelopus)." Systematics & Biodiversity, 9, 45–57.

Scheele, B. C., Pasmans, F., Skerratt, L. F., Berger, L., Martel, A. N., Beukema, W., Acevedo, A. A., Burrowes, P. A., Carvalho, T., Catenazzi, A., and De la Riva, I. (2019). "Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity." Science, 80-(363), 1459–1463. [link]

Stuart, S. N., Hoffman, M., Chanson, J., Cox, N., Berridge, R., Ramani, P. & Young, B. (2008). Threatened amphibians of the world. Lynx Editions, Barcelona, Spain.

Originally submitted by: Jiarong Chang, Emma Steigerwald (2022-02-09)
Description by: Jiarong Chang, Emma Steigerwald (updated 2022-02-09)
Distribution by: Jiarong Chang, Emma Steigerwald (updated 2022-02-09)
Life history by: Jiarong Chang, Emma Steigerwald (updated 2022-02-09)
Trends and threats by: Jiarong Chang, Emma Steigerwald (updated 2022-02-09)
Comments by: Jiarong Chang, Emma Steigerwald (updated 2022-02-09)

Edited by: Ann T. Chang (2022-02-09)

Species Account Citation: AmphibiaWeb 2022 Atelopus loettersi <> University of California, Berkeley, CA, USA. Accessed Mar 3, 2024.

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Citation: AmphibiaWeb. 2024. <> University of California, Berkeley, CA, USA. Accessed 3 Mar 2024.

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