Distribution and Habitat

Country distribution from AmphibiaWeb's database: Colombia, Ecuador

View distribution map in BerkeleyMapper.

Nymphargus balionotus can be found from the Western slope of the Cordillera Occidental of the Andes, from Ecuador to Colombia. At the time of the species description, approximately 51 specimens were reported across the provinces Carchi, Imbabura, and Cotopaxi, of Ecuador (Guayasamin et al. 2020). Later, they were found in the provinces Cauca and Valle del Cauca, Colombia, from the elevations of 460 to 1,540 meters (Maynard et al. 2020). These areas are characterized by evergreen forests with a tree canopy generally under 25 meters and includes many epiphytic plants. Nymphargus balionotus can be found on vegetation along streams (Guayasamin et al. 2020).

Life History, Abundance, Activity, and Special Behaviors
Nymphargus balionotus is nocturnal and are arboreal, preferring to live in trees along streams. Specifically, they can be found resting on the surfaces of leaves. Species abundance is correlated with high rainfall areas and seasons, while drier areas and seasons have fewer sightings (Guayasamin et al. 2020).

Nymphargus balionotus deposit their eggs on leaves, mosses, rocks, branches in riparian areas (Díaz-Ricaurte and Guevara-Molina 2020, Guayasamin et al. 2020).

Most species within the Nymphargus genus have a completely transparent ventral peritoneum or stomach tissue (Díaz-Ricaurte and Guevara-Molina 2020).

Trends and Threats
The species is listed as “Endangered” by the IUCN Red List, with only a single reproducing, but declining, population being known in Ecuador. The most prevalent threats to the species are climate change and habitat loss. The cause of habitat loss for N. balionotus include mining operations and agricultural expansion in the area. The fungus Batrachochytrium dendrobatidis is also hypothesized to be a threat, but more testing needs to be conducted before a conclusion can be made (Guayasamin et al. 2020).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Mining
Habitat fragmentation
Predators (natural or introduced)
Disease
Climate change, increased UVB or increased sensitivity to it, etc.

Comments
Maximum Likelihood analysis of 12S rRNA and 16S rRNA mtDNA indicate that N. balionotus is sister to B. manduriacu. The next most closely related clade is composed of N. chancas and N. mariae (Guayasamin et al. 2019).

The specific epithet “balionotus” is derived from the greek words “balios” meaning “spotted, dappled” and “notos” meaning “back”, and is in reference to the dorsal patterning of the species (Guayasamin et al. 2020).

The species was first described by William Duellman in 1981 as Centrolenella balionota. It has also been placed in the genera Cochranella, Centrolene, and Cochranella, before being assigned to Nymphargus by Guayasamin et al. (2019, Guayasamin et al. 2020).

References

Díaz-Ricaurte, J.C., Guevara-Molina, C.E. (2020). “Morphological and molecular data reveal new country records and distribution extensions of some glassfrogs (Anura: Centrolenidae) for Colombia.” Studies on Neotropical Fauna and Environment, 57(1): 51-65 [link]

Guayasamin, Cisneros-Heredia, D. F., McDiarmid, R. W., Pena, P., Hutter, C. R. (2020). “Glassfrogs of Ecuador: Diversity, Evolution, and Conservation.” Diversity (Basel), 12(6), 222 [link]

Guayasamin, J. M., Cisneros-Heredia, D. F., Vieira, J., Kohn, S., Gavilanes, G., Lynch, R. L., Hamilton, P. S., Maynard, R. J. (2019). “A new glassfrog (Centrolenidae) from the Chocó-Andean Río Manduriacu Reserve, Ecuador, endangered by mining. PeerJ, 7, e6400. [link]

Maynard, R. J., Trageser, S. J., Kohn, S., Hamilton, P. S., Culebras, J., Guayasamin, J. M. (2020). "Discovery of a reproducing population of the Mindo Glassfrog, Nymphargus balionotus (Duellman, 1981), at the Río Manduriacu Reserve, Ecuador, with a literature review and comments on its natural history, distribution, and conservation status." Amphibian Reptile Conserv, 14(2), 172-184 [link]

Species Account Citation: AmphibiaWeb 2022 Nymphargus balionotus: Mindo Glassfrog <https://amphibiaweb.org/species/1755> University of California, Berkeley, CA, USA. Accessed Jan 22, 2025.

Citation: AmphibiaWeb. 2025. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 22 Jan 2025.

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