Description
Chiropterotriton casasi is a relatively large, stout-bodied, and long-legged salamander described from four males and one female. The snout-vent length range in males is 34.5 - 42.0 mm and 40.9 mm in the female specimen. The total length of the body in males ranges between 36.8 - 42.9 mm, however female total length is unavailable as the specimen had a broken tail. The head is moderately wide and broad, and the snout is truncated. The head is about twice as long as it is wide in males, while less long relative to width in females. Males have a mental gland. The eyes protrude from the body and extend past the jawline. Males have distinct jaw muscles located behind the eyes. Head depth ranges from 2.1 - 2.6 mm in males and is 2.6mm in the one female. Males had 8 - 11 vomerine teeth and the female had 13 vomerine teeth. Forelimb lengths were slightly less than half the hind limb length. When the limbs are adpressed towards each other along the body, the either touch or are separated by one costal fold. The digits show some webbing; the first toe is small and does not extend past the webbing while the remaining four toes are long and slender. The tails are approximately the same length as the snout-vent length (Parra Olea et al. 2020).

DIAGNOSIS:

In general, C. casasi differs from C. aureus, C. ceronorum, C. lavae, C. melipona, C. nubilus, C. orculus, C. perotensis, and C. totonacus because of its larger body size in adults. When compared to C. chriopterus the female has a larger body size. Chiropterotriton casasi can be distinguished from C. chriopterus, C. melipona, C. nubilus, and C. totonacus due to its shorter tail. When compared to all of the species listed above C. casasi can be distinguished by its longer head except for C. totonacus, in which only the female C. casasi head is longer. Chiropterotriton casasi also has a broader head than all listed with the exceptions of C. chriopterus and C. totonacus. Chiropterotriton casasi has shorter limbs than C. lavae and C. totonacus and longer limbs than C. aureus, C. melipona, C. nubilus, and C. orculus (Parra Olea et al. 2020).

COLORATION:

Only coloration in preservatives is known. Preserved specimens are a faded brown color, with mottled snout and limb coloration and a paler head and ventrum. There may be a pale band between the eyes. The dorsal end of the tail has a light stripe (Parra Olea et al. 2020).

VARIATION:

Most of the morphologic measurements for both sexes are within the same intervals, except for the number of vomerine and maxillary teeth, which are more numerous in the female. The female specimen is mottled over its entire body, which is faded and dark brown. The female specimen also shows a light dorsal stripe at the base of the tail. Some specimens also exhibit a pale interorbital band (Parra Olea et al. 2020).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Mexico

View distribution map in BerkeleyMapper.

Chiropterotriton casasi was found near the border of the States of Veracruz and Puebla in Mexico, 13 miles southwest of the town of Tlapacoyan. The habitat in which C. casasi was collected in 1969 has been heavily altered by agriculture and logging and is currently composed of secondary growth forest. The species was found in montane forest when first collected. The elevational range of the species is 1450 - 1550 m (Parra Olea et al. 2020).

Life History, Abundance, Activity, and Special Behaviors
Chiropterotriton casasi can potentially be found in sympatry with C. ceronorum, C. chiropterus, C. lavae, C. melipona, C. perotensis, and C. totonacus (Parra Olea et al. 2020).

Trends and Threats
Chiropterotriton casasi is very rare, with only five recorded specimens from one location since 1969. Its habitat has been fragmented and disturbed by agriculture and logging industries, leaving little of the original habitat intact. No specimens of this species have been found since 1969 (Parra Olea et al. 2020). IUCN has listed them as “Critically Endangered” and they are possibly extinct (IUCN 2021).

Possible reasons for amphibian decline

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

Comments

PHYLOGENETIC RELATIONSHIPS:

Chiropterotriton casasi was placed in the genus Chiropterotriton based on morphometric and osteological comparisons because genetic material is not available for phylogenetic analysis. As such, its exact placement in the genus is unknown as of 2022 (Parra Olea et al. 2020).

ETYMOLOGY:

The species epithet, “casasi” is in honor of Mexican herpetologist Gustavo Casas Andreu who greatly contributed to the biodiversity of Mexican amphibians and reptiles (Parra Olea et al. 2020).

References

IUCN SSC Amphibian Specialist Group. (2021). "Chiropterotriton casasi." The IUCN Red List of Threatened Species 2021: e.T182502187A182502425. https://dx.doi.org/10.2305/IUCN.UK.2021-1.RLTS.T182502187A182502425.en. Accessed on 23 February 2022.

Parra Olea, G., Garcia-Castillo, M. G., Rovito, S. M., Maisano, J. A., Hanken, J., Wake, D. B. (2020). “Descriptions of five new species of the salamander genus Chiropterotriton (Caudata: Plethodontidae) from eastern Mexico and the status of three currently recognized taxa.” PeerJ, 8:e8800 [link]

Species Account Citation: AmphibiaWeb 2022 Chiropterotriton casasi: Tlapacoyan Salamander <https://amphibiaweb.org/species/9197> 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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