Description
Bolitoglossa xibalba is a salamander with a snout-vent length of about 43 to 50 mm. One individual has a total length of 77.3 mm. Their heads are about a quarter longer than wide. Their legs are somewhat long, and they have wide, webbed hands and feet. A distinguishing character is a protruding, triangular third toe on both hands and feet, which is easier to identify on the hands. The other toes are rounder and shorter (Campbell et al. 2010).

Their webbed feet are wider than most, but less webbed than B. hartwegi, which it is most similar to. Bolitoglossa xibalba also has longer limbs than B. hartwegi. The amount of webbing is similar in B. mexicana, B. rufescens, and B. occidentalis, but B. xibalba is smaller and less brightly patterned than B. mexicana and slightly larger than B. rufescens and B. occidentalis. Bolitoglossa xibalba’s protruding third toe also helps to set them apart, and though B. stuarti also has a protruding third toe, B. xibalba has a smaller snout-vent length. Bolitoglossa xibalba also has less uniform patterning than B. stuarti or B. hartwegi (Campbell et al. 2010).

There is a wide variety of patterns, but B. xibalba tend to have a dark gray or brown dorsum and paler white, pink, or lavender flanks. Their venters are also pale, and often have spots or smudges of darker colors. Black speckled markings are common on the dorsum, and small black or brown dots can usually be found on the flanks as well. They often have dark markings that reach from the snout, past the eye, to the neck, either as a single canthal line, or a more Y-shaped mark (Campbell et al. 2010).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Guatemala

View distribution map in BerkeleyMapper.

Bolitoglossa xibalba have been exclusively found in Guatemala. They have been identified in the Sierra de los Cuchumatanes that spans the regions of El Huehuetenango and El Quiche, the region between San Mateo Ixtatan and San Juan Ixcoy, and the Montanas del Cuilco, and in the region north of Uspantan, Guatemala. The specimens collected have exclusively been found between 1980 - 3220 meters above sea level. Bolitoglossa xibalba inhabit moist forest environments, where many of the specimens have been found under bark and moss of tree trunks (Campbell et al. 2010).

Life History, Abundance, Activity, and Special Behaviors
Specimens of B. xibalba have been found living in the terrestrial environment, inhabiting moist forest regions at the elevation range of 1980 - 3220 meters above sea level (IUCN 2020, Campbell et al. 2010).

Although it is unclear whether this species is nocturnal or diurnal, collected specimens have been observed above the surface during the evening and night. This species does not possess any migration behavior (IUCN 2020).

Bolitoglossa xibalba is presumed to lay eggs in moist environments on terrestrial or arboreal substrates and to undergo direct development (Johnson et al. 2015).

Trends and Threats
Bolitoglossa xibalba has an Environmental Vulnerability Score of 17 - based on distribution, diversity of habitats, and reproductive mode - and is classified as highly vulnerable to environmental degradation (Johnson et al. 2015).

Bolitoglossa xibalba is listed as “Endangered” by the IUCN Red List. The species was common in the 1990’s, but has been less abundant in recent years, possibly due to low survey efforts (IUCN 2020). Habitat loss is the major threat to this species, specifically loss of habitat to logging and coffee plantations. Another potential threat is chytrid fungal disease that are tied to the pet trade, and potentially climate change as well (Glime et al. 2017, IUCN 2022, Norris 2007).

Relation to Humans
Local people sometimes kill salamanders because they are thought to be poisonous. This indiscriminate extermination could include B. xibalba (IUCN 2022).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Drainage of habitat
Habitat fragmentation
Disease
Intentional mortality (over-harvesting, pet trade or collecting)
Climate change, increased UVB or increased sensitivity to it, etc.

Comments
Bayesian Inference on the mitochondrial DNA 12S ribosomal subunit gene placed B. xibalba as sister to B. hartweg. The next most closely related species is B. stuarti. Together they are placed under subgenus Mayamandra (Campbell et al. 2010).

Bolitoglossa xilbalba was named for Xibalba, the mythical Mayan underworld. As the species inhabits montane forests at high elevations, the name also pays tribute to those who have perished in said highlands in the Guatemalan civil war, which lasted from 1960 to 1996 (Campbell et al. 2010).

References

Campbell, J. A., Smith, E. N., Streicher, J., Acevedo, M. E., Brodie, E. D. Jr. (2010). "New salamanders (Caudata: Plethodontidae) from Guatemala, with miscellaneous notes on known species." Miscellaneous Publications Museum of Zoology University of Michigan, 200, 1-66. [link]

Glime, J. M., Boelema, W. J. (2017). "Salamander Mossy Habitats." Brophyte Ecology. Glime, J. M., eds., Michigan Technological University and the International Association of Bryologists, Michigan. [link]

IUCN SSC Amphibian Specialist Group. (2020). "Bolitoglossa xibalba." The IUCN Red List of Threatened Species 2020: e.T194325A2312661. https://dx.doi.org/10.2305/IUCN.UK.2020-2.RLTS.T194325A2312661.en. Accessed on 24 February 2022.

Johnson, J.D., Mata-Silva, V., Wilson, L.D. (2015). “A conservation reassessment of the Central American herpetofauna based on the EVS measure.” Amphibian and Reptile Conservation, 9(2), 1-94. [link]

Norris, S. (2007). “Ghosts in our midst: Coming to terms with amphibian extinctions.” BioScience, 57(4), 311–316. [link]

Species Account Citation: AmphibiaWeb 2022 Bolitoglossa xibalba <https://amphibiaweb.org/species/7571> University of California, Berkeley, CA, USA. Accessed Nov 21, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 21 Nov 2024.

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