Description
Chiropterotriton lavae is a small salamander that has a male snout to vent length range of 31.0 - 33.8 mm and a female range of 27.9 - 34.9 mm (García-Castillo et al. 2018). Its head is around 6 mm wide and is more broad than its body. The dorsal surface of the head and snout is flat and uniformly pitted. Chiropterotriton lavae has a narrowed snout that truncates anteriorly. The distance between its orbits, which is around 2 mm, is longer than the distance between eyelids, which measures 1.2 mm. The nuchal fold on its throat curves back on the side of the neck, and curves forward to meet the mid-dorsal line. A vertical groove at the back of the jaw angle reaches the dorsal surface of the neck. An indistinct groove connects the two vertical grooves. Chiropterotriton lavae has 25 - 26 maxillary-premaxillary teeth on each side of the jaw. It has six vomerine teeth on each side curving backwards, which are separated medially by a distance more than the distance between two teeth. Its parasphenoid teeth arrange in double series, separated medially by a narrow interval. Males have from three to five maxillary-premaxillary teeth on each side, and premaxilla piercing the lip. The tips of its toes are rounded. The toes touch or slightly overlap when limbs are adpressed. Chiropterotriton lavae has 11 costal grooves (Taylor 1942). See Taylor 1942 for more description.

DIAGNOSIS:

The species is diagnosed by its unique dentition and its relatively large limbs and feet adapted for arboreal habitats (Taylor 1942). A comparison with C. aureus and C. nubilus can be found in García-Castillo et al. 2018.

COLORATION:

Chiropterotriton lavae are dull brown with spots of dark color. The spots are more concentrated in the dorsolateral region. The dorsal surface at the base of the tail has two short cream diagonal lines (Taylor 1942). It is unclear if this is in life or in preservative.

VARIATION:

There is considerable variation in color patterns in paratypes (Taylor 1942).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Mexico

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (1 records).

Chiropterotriton lavae is only found in pine-oak woodlands and cloud forests between Toxtlacuaya and La Joya, central-western Veracruz, Mexico at 2000 to 2200 m elevation (Amphibian 2020).

Life History, Abundance, Activity, and Special Behaviors
Chiropterotriton lavae is a very agile species (Raffaëlli 2014).

Chiropterotriton lavae lives on bromeliads (genus Catopsis) that grow on trunks in mixed pine-oak forest near La Joya, Veracruz, at 2100 m. The air temperature at which C. larvae were found was 25.4°C and the temperature in the bromeliads was 20.2°C (Raffaëlli 2014). All of the C. larvae salamanders were found on bromelias. The species had high occurrences when flipping the foliage of bromeliads before the introduction of mining and consequent deforestation (Parra-Olea 1999).

Chiropterotriton lavae was observed abundantly in the summer of 2003 when the forest was deforested because of the construction of a quarry that extracts volcanic rocks. By September 2004, almost 50% of the forest had disappeared due to the advancement of the quarry, and by 2013, it had almost completely disappeared (Raffaëlli 2014).

Snakes in the Rhadinaea family that feed on the salamander were observed at the bottom of a bromeliad (Raffaëlli 2014).

Larva
As a member of family Plethodontidae, C. lavae is presumed to reproduce via direct development.

Trends and Threats
In 1987, C. larvae was considered to be resilient to habitat fragmentation, and many of them could be found as long as bromeliads in the cloud forests in Jalapa, Veracruz, Mexico were not disturbed (Wake 1987). However by 1999, the impact of deforestation, logging and mining on the salamander were evident to researchers (Parra-Olea 1999). By 2013, the species had almost completely disappeared (Raffaëlli 2014). The species is also impacted by energy production, mining, quarrying, and fire and fire suppression (IUCN 2016).

Comments

PHYLOGENETIC RELATIONSHIPS:

Bayesian Inference and Maximum Likelihood analyses of 12S,16S, and COI mitochondrial DNA revealed that there are two main groups within the Chiropterotriton genus, the southern clade and the northern clade, which are geographically isolated from each other. Chiropterotriton lavae belongs to the southern clade in which four named species and seven unnamed species are included as opposed to 12 in the northern clade. Chiropterotriton lavae is most closely related to species that were unnamed in 2018. Each of the southern clade species occur in geographic proximity but are found in different elevation and environmental conditions (García-Castillo et al. 2018).

This species was featured in News of the Week 19 August 2024:

Population genetics is a field of biology that studies genetic variation and the processes that shape it, including mutation, natural selection, genetic drift (random change over time), gene flow, and recombination. Salamanders present compelling questions for population geneticists because they have very large genomes – including some of the largest known in vertebrates. Rios-Carlos et al. (2024) explore the population genetic consequences of large genomes in a group of salamanders, and find that salamanders don’t necessarily play by the same rules as other animals. Because only one or two crossing-over events occur per chromosome during meiosis, larger genomes are predicted to have relatively low rates of recombination per base pair of the genome. This should negatively impact salamanders with giant genomes by reducing the ability of selection to remove deleterious mutations or fix beneficial ones. However, they find that salamanders have mutation patterns resulting from selection that seems to be just as efficient as is the case for organisms with normal-sized genomes. Their finding leads to questions such as how salamander genomes have grown so large, whether they have unique adaptations such as additional crossing over events during meiosis, and if having large genomes is somehow beneficial to them in ways we have yet to understand. (Rebecca Tarvin).

References

Amphibian Species of the World (2020). “Chiropterotriton lavae (Taylor, 1942)” Amphibian Species of the World 6.0, an Online Reference. https://amphibiansoftheworld.amnh.org/Amphibia/Caudata/Plethodontidae/Hemidactyliinae/Chiropterotriton/Chiropterotriton-lavae Accessed in November 2020

García-Castillo MG, Soto-Pozos ÁF, Aguilar-López JL, Pineda E, Parra-Olea G. (2018). “Two new species of Chiropterotriton (Caudata: Plethodontidae) from central Veracruz, Mexico.” Amphibian and Reptile Conservation 12(2) [Special Section]: 37–54 (e167). [link]

IUCN SSC Amphibian Specialist Group. (2016). “Chiropterotriton lavae.” The IUCN Red List of Threatened Species 2016: e.T59226A53978402. https://dx.doi.org/10.2305/IUCN.UK.2016-1.RLTS.T59226A53978402.en. Accessed in November 2020.

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.

Raffaëlli, J. (2007). Les Urodèles du monde. Penclen Edition, France.

Taylor, E. H. (1942) “New Caudata and Salientia from México.” University of Kansas Science Bulletin 28(14), 295–323. [link]

Wake, D. B. (1987). ''Adaptive radiation of salamanders in Middle American cloud forests.'' Annals of the Missouri Botanical Garden, 74(2), 242-264.

Species Account Citation: AmphibiaWeb 2024 Chiropterotriton lavae: Pygmy Splayfoot Salamander <https://amphibiaweb.org/species/4032> University of California, Berkeley, CA, USA. Accessed Dec 12, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 12 Dec 2024.

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