El Chico Salamander; Salamandra de El Chico
Species Description: Garcia-Castillo MG, Rovito SM, Wake DB, Parra-Olea G 2017 A new terrestrial species of Chiropterotriton (Caudata: Plethodontidae) from central Mexico. Zootaxa 4363: 489-505.
© 2017 Sean Michael Rovito (1 of 7)
ADULT MORPHOLOGY:Chiropterotriton chico is commonly known as El Chico Salamander and is one of the larger species within the genus. The males in this species have a snout-vent length range of 36.2 – 42.6 mm while females have a snout-vent length of 35.9 – 44.3 mm. The head in both sexes are narrow and fairly long. Within this species of salamander, both males and females have jaw muscles, which are visible and appear to be like swollen masses on the head right behind the eyes. In the ventral view the eyes seem as if they are popping out laterally, extending beyond the jaw. There are no visible parotoid glands and the males’ mental glands are among one of the smallest from its genus. The limbs in this species are moderately thin. The hands are slightly smaller in width than the feet. The relative finger length is I < IV < II < III. Their feet are wider than most species in this genus with males averaging 4.1 mm and females averaging 4.2 mm. Something distinct about both the females’ and males’ feet is that the digits are obvious, skinny and extend pass the medium webbing they have. Their relative toe lenghts are I < V < II < IV < III, where their third digit well developed. This species’ tail is among one of the longest. The tail length of males is usually 40.4 – 49.5 mm while the females is 37.0 – 49.0 mm (García-Castillo et al. 2017).
Similar species to C.chico are C. orculus and C. arboreus. Although they are very similar by having a dark brown dorsum, C. chico has a reddish line extending from the back of the eyes towards the tail where it starts and ends with some yellow spots, while the other two species do not. Compared with C. orculus, C. chico has a longer-wider body with a longer tail, longer limbs and a longer, yet less narrow head (Parra Olea et al. 2020). Compared to C. arboreus, C. chico has a larger-longer body, with a longer wider head, but has shorter limbs in both female and males. In a preserved state, the wider feet of the C. chico are a faintly darker tan color with darker specs on the top part of the feet going towards the digits (Garcia-Castillo et al. 2017).
COLORATION:Coloration in life of this species was described as another Chiropterotriton species, C. multidentatus from Hidalgo, Mexico by Rabb in 1958. The species is dark lavender-brown all over the body but with a cream or tan color on the ventrum. This species also has a lighter face compared to the rest of the body and a cream-reddish colored strip on the center of its back going towards the tail (Rabb 1958).
Coloration preserved in alcohol of C. chico is a dark tannish brown all over its back, becoming a paler tan on the sides and a very pale cream on the ventral side. The snout has patches that are dark and light brown. It also has some yellow spots behind the eye area and at the end of the tail. This species has a reddish line that is on the center of the back, starting from behind the eye and extending towards the tail, which is outlined by a yellow line on each side. While the whole tail is a much darker brown compared to the body, the limbs and top of its hands and feet are a lighter brown (Garcia-Castillo et al. 2017).
VARIATION:Although C. chico are among the largest salamander in their genus; the females are usually larger than males. Males have more teeth than the females (Rabb 1958), tend to have a shorter and wider snout, and a relatively longer tail than females. Another distinctly different between these sexes is that the females have adpressed front and hind limbs that are separate by two costal folds while males are only separated by 0.6 folds (Garcia-Castillo et al. 2017).
Distribution and Habitat
Life History, Abundance, Activity, and Special Behaviors
According to the IUCN Red List, C. chico undergoes direct development (IUCN 2020).
Observations of the ovaries and oviducts from females in this genus inhabiting Hidalgo, show that females appear to be reproductively mature at 35 – 36 mm snout-vent length. From published studies on other plethodontids, it can be said that individuals in the Chiropterotriton genus may become reproductively active once they reach two years of age. From five females who were found in Hidalgo, spermatophore capsules were observed to be lodged in their cloaca. In this same sample from 1951, the female had large eggs of 2.0 - 2.5 mm in diameter, swollen oviducts, and 3 - 7 eggs on the side (Rabb 1985).
This species is not a migrant, so they do not move particularly long distances (IUCN 2020).
Trends and Threats
The population decrease has been hypothesized to be due to Batrachochytrium dendrobattidis(Garcia-Castillo et al. 2017, IUCN 2020), a pathogenic chytrid fungus (Cheng et al. 2011). This fungal disease has been increasing since its first description in 1974 (Parra-Olea et al. 1999). The IUCN suggests that more research should be done for the understanding of C. chico’s population trends and threats.
Possible reasons for amphibian decline
PHYLOGENETIC RELATIONSHIPS:Through Bayesian analysis of 16S mtDNA, C. chico has been placed in the clade containing C. arboretus, C. cieloensis, C. cracens, C. infernalis, C. multidentatus, and C. terrestris. Chiropterotriton chico is sister to C. terrestris with a 2.8% divergence Kiumara-two parameter (K2P) distance and uncorrected distance (Garcia-Castillo et al. 2017).
Chiropterotriton chico was named to reference the location it is found, El Chico National Park in Hidalgo, Mexico (Garcia-Castillo et al. 2017).
Cheng, T.L., Rovito, S.M., Wake, D.B., Vredenburg, V.T. (2011). ''Coincident mass extirpation of neotropical amphibians with the emergence of the infectious fungal pathogen Batrachochytrium dendrobatidis.'' Proc. Natl. Acad. Sci., 108, 9502–9507.
García-Castillo, M., Rovito, S., Wake, D., Parra-Olea, G. (2017). "A new terrestrial species of Chiropterotriton (Caudata: Plethodontidae) from central Mexico." Zootaxa, 4363(4), 489-505. [link]
IUCN SSC Amphibian Specialist Group. 2020. "Chiropterotriton chico". The IUCN Red List of Threatened Species 2020: e.T150088945A150088952. https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T150088945A150088952.en. Downloaded on 17 February 2021.
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]
Parra-Olea, G., García-París, M., and Wake, D. B. (1999). ''Status of some populations of Mexican salamanders (Amphibia: Plethodontidae).'' Revista de Biología Tropical, 47, 217-223.
Rabb, G. B. (1958). ''On certain Mexican salamanders of the plethodontid genus Chiropterotriton.'' Occasional Papers of the Museum of Zoology, 587, 1-37.
Originally submitted by: Karen Chen, Alexes Juárez, Clarissa Mora Ruelas (2021-08-12)
Description by: Karen Chen, Alexes Juárez, Clarissa Mora Ruelas (updated 2021-08-12)
Distribution by: Karen Chen, Alexes Juárez, Clarissa Mora Ruelas (updated 2021-08-12)
Life history by: Karen Chen, Alexes Juárez, Clarissa Mora Ruelas (updated 2021-08-12)
Trends and threats by: Karen Chen, Alexes Juárez, Clarissa Mora Ruelas (updated 2021-08-12)
Comments by: Karen Chen, Alexes Juárez, Clarissa Mora Ruelas (updated 2021-08-12)
Edited by: Ann T. Chang (2021-08-12)
Species Account Citation: AmphibiaWeb 2021 Chiropterotriton chico: El Chico Salamander; Salamandra de El Chico <https://amphibiaweb.org/species/8745> University of California, Berkeley, CA, USA. Accessed Oct 18, 2021.
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Citation: AmphibiaWeb. 2021. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 18 Oct 2021.
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