Description
Charadrahyla taeniopus has a male snout-vent length that reaches a maximum of 65.9 mm and females have a longer maximum length of 70 mm. The head width is as wide as the flattened body. The snout of C. taeniopus is different between the sexes; the males have a pointed snout while the females have a truncated snout. The tympanum is distinct and is not connected to the eye. The pupil is a horizontal slit (Flores Hernández 2014). The fingers and toes are thin and long with rounded, equally sized discs on the tips. Webbing is present for both toes and fingers. The finger webbing formula is I 2-2 ¼, II 1¼-2, III 2-1 IV and the relative length of fingers is I < II < IV < III. The foot webbing formula is ¾-½, II ½-2, III 1-2, IV 2-¾ V. The body has distinguishing features, such as tarsal folds on the limbs. The skin texture of the Charadrahyla genus in life is granular for both the dorsum and ventrum and is thick on the limbs (Campbell et al. 2009). The species is unusual in that the males may lack a vocal sac, although sources are unclear on this (Smith and Taylor 1948). However, species in this genus have nuptial pads, which are composed of dark-colored spinules (Campbell et al. 2009). Some species of the genus, including C. taeniopus, have relatively enlarged testes (Faivovich et al. 2005).

For C. taeniopus tadpoles, the total length at Stage 31 is 43.5 mm. The body shape can be described as rounded, with a slight depression of the underside of the snout. The tail meets with the entirety of the posterior of the body and the narrow end of the tail tips upwards. Both the eyes and the nostrils are located dorsally and close to one another. The spiracle is on the sinistral side while the vent is on the dextral side. The mouth of the tadpole is on the ventral side. The oral disc has upper and lower jaw sheaths that are keratinized. The sheaths are darkly colored on the edges where the small serrations lie (Kaplan and Heimes 2015). The mouth has two or three upper rows of teeth and three or four lower rows of teeth with lips bordered by papillae (Flores Hernández 2014)

Charadrahyla taeniopus and Ecnomiohyla miotympanum are the only frogs that have range overlaps in the municipality of Atzalan. They are differentiated by size, with E. miotympanum being smaller. Charadrahyla taeniopus is differentiated within its genus by a brownish black belly with yellow flecks (Flores Hernández 2014).

In life, the Charadrahyla genus is known for large patches of brown on the dorsal side (Campbell et al. 2009). Both sexes of the C. taeniopus have yellow dots with background colors of black and brown on the belly. The throat is colored white and silver while the lateral part of the body is a dark brown with yellow spots. Both sexes have clear palpebrum and bronze or grayish tan irises. Sexual dimorphism is demonstrated with female C. taeniopus having reddish brown as the dorsal color with brown markings instead of blackish-brown with yellow spots (Flores Hernández 2014).

In life, tadpoles have a reddish brown background with gold spots while the tail is a reddish cream color and the fins a gray color. In preservative, the color of a tadpole body is light brown while the tail is a cream color (Kaplan and Heimes 2015).

The females vary from the males with brown markings on their backs and the background color being a reddish brown. Females also have a truncated snout, while male snouts are pointed (Flores Hernández 2014).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Mexico

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (2 records).

Charadrahyla taeniopus naturally occurs in many parts of Mexico, mostly the Sierra Madre Oriental. The species can be found from Hidalgo del Parral in the northeastern part of the country to the eastern coastal city of Veracruz to the southern Puebla (Santos-Barerra and Canseco-Márquez 2004). The forests that these frogs inhabit occur at a range of 1100 to 2200 m. In these highlands, C. taeniopus needs humid cloud forests (Santos-Barrera and Canseco-Márquez 2004). The humidity also contributes to riparian vegetation, which is necessary for the survival of the species (Flores Hernández 2014).

Life History, Abundance, Activity, and Special Behaviors
Charadrahyla taeniopus is a nocturnal and arboreal species that inhabits the cloud forests located in the Hidalgo-Veracruz region of Mexico (Santos-Barerra and Canseco-Márquez 2004).

Summer rains signal the beginning of the reproductive season (Guzmán 2011). During this period of time, the frogs will migrate from the highlands to the streams where they will spawn (Flores Hernández, 2014). Residents of the Atzalan specify the Alseseca River as the primary location where frogs are present, with other seasonal streams and ponds being alternative breeding grounds. Streams with a slow moving current are ideal for reproduction, during which the male utilizes axillary amplexus, gripping around the female under her arms while stimulating her with calluses on his hands to induce egg release (Flores Hernández 2014).

After the eggs have been fertilized and hatched, the free-swimming larvae can experience rapid larval growth at a temperature range of 20 to 25°C. This growth can take three to twenty days, during which the tadpole will feed on algae and detritus (Flores Hernández 2014).

After metamorphosis into the adult stage this species will adopt an insect-based diet (Guzmán 2011).

Trends and Threats
Charadrahyla taeniopus is a declining species due to factors such as habitat destruction and pollution from pesticides (Valdespino et al. 2015). As a whole, amphibians are threatened due to the loss of habitat, which is often converted into farmland for agricultural purposes (Flores Hernández 2014). With less forest to reside in, the species become more exposed to sun and heat with lack of water (Aguilar 2000). Furthermore, pesticides such as DDT are found within the habitat range of the C. taeniopus in large quantities and can remain in the environment for decades. The frog absorbs the pesticide through the skin or by consuming prey that is contaminated by the pesticide, leading to bioaccumulation in the body. These chemicals negatively impact the reproductive cycle and overall health of the species, leading to a decreasing population (Valdespino et al. 2015).

Along with environmental damage, direct capture by humans is also harming the population numbers. Charadrahyla taeniopus is eaten by locals and captured for trading purposes. This species does not occur in protected areas, as the montane forests are not currently set aside as a national park (Santos-Barerra and Canseco-Márquez 2004).

Relation to Humans
Charadrahyla taeniopus is a representative of the municipality of Atzalan, Veracruz. They are featured on the municipal shield of Atzalan as well as several other monuments, and have been a major food source for residents from the time of the Aztecs (Flores Hernández 2014).

The capture of these frogs is associated with tradition. The Atzalan people believe that the frogs rain down each year on the same date that the patrons San Andrés Apóstol and Archangel Michael were venerated, September 29th. It is true that C. taeniopus descend from highlands to reproduce in streams during the first rains of summer (Flores Hernández 2014).

The species has a high economic value, worth 30 to 40 pesos per dozen frogs (Quiroz et al. 2012). They can be cooked in soups or made into Calate cakes, worth 100 to 200 pesos in some establishments. While many locals claim that captured frogs are destined for home consumption, some are only interested in selling them (Flores Hernandez 2014). Other reasons for the capture of these frogs include medicine and the pet trade (Santos-Barerra and Canseco-Márquez 2004).

Although C. taeniopus is in decline, 48% of respondents from Atzalan, Veracruz, do not believe that it is (Flores Hernández 2014).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Local pesticides, fertilizers, and pollutants
Intentional mortality (over-harvesting, pet trade or collecting)
Climate change, increased UVB or increased sensitivity to it, etc.

Comments
The species authority is: Günther, A. C. L. G. (1901). Reptilia and Batrachia. Part 164. Salvin, O., and F. D. Godman eds., Biologia Centrali Americana. Volume 7: 253–260. London, R. H. Porter and Dulau & Co.

The Charadrahyla group is found within the paraphyletic group of Neotropical hylids (Campbell et al. 2009). As of 2005, there were five species within the Charadrahyla taeniopus group: C. altipotens, C. chaneque, C. nephila, C. taeniopus, and C. trux (Faivovich et al. 2005).

The species C. taeniopus was originally placed in the genus Hyla, in the Hyla taeniopus group, before being moved to Charadrahyla (Faivovich et al. 2005).

There is currently no significant evidence that the Charadrahyla group is monophyletic (Faivovich et al. 2005).

Before diverging into several other genres, the monophyly of Hyla was supported by a 24 or more chromosome karyotype and an extra tendon on the tendo superficialis digiti V (Faivovich et al. 2005).

Charadra means “ravine” in Greek and refers to the habitat in which these frogs live (Faivovich et al. 2005). The latter part of the genus name, hyla, is a feminine form of Hylas, which refers to a comrade of Hercules in Greek mythology. Hylas was said to have approached a forest stream where water nymphs pulled him under, enamoured by his beauty (Myers 2006).

Charadrahyla taeniopus is known as Calates to the locals of Atzalan, Veracruz (Flores Hernández 2014).

When locals prepare Calates to eat, the frogs cross their arms much like a human when they are introduced to boiling water. No other species of frog is known to do this in Atzalan (Flores Hernández 2014).

References

Aguilar, S. (2000). ''El festín de las ranas.'' Pronatura: Revista trimestral , 10, 36-38.

Campbell, J. A., Blancas-Hernández, J. C., Smith, E. N. (2009). ''A new species of stream-breeding treefrog of the genus Charadrahyla (Hylidae) from the Sierra Madre del Sur of Guerrero, Mexico.'' Copeia, 2009(2), 287-295. [link]

Faivovich, J., Haddad, C. F. B., Garcia, P. C. A., Frost, D. R., Campbell, J. A., Wheeler, W. C. (2005). ''Systematic review of the frog family Hylidae, with special reference to Hylinae: phylogenetic analysis and taxonomic revision.'' Bulletin of the American Museum of Natural History, (294), 1-240. [link]

Flores-Hernández, D. (2014). ''El calate Charadrahyla taeniopus (Günther, 1901) recurso alimentario en el municipio de Atzalan, Ver.'' Thesis. Universidad Veracruzana.

Guzmán, S. G. (2011). Anfibios y reptiles de Veracruz: Guía ilustrada. Gobierno del Estado de Veracruz, Consejo Veracruzano de Ciencia y Tecnología, 2011

Kaplan, M., Heimes, P. (2015). ''The Tadpole of the Mexican Tree Frog Charadrahyla taeniopus (Anura: Hylidae).'' Caldasia, 37(2), 393-396.

Myers, C. W., Stothers, R. B. (2006). ''The myth of Hylas revisited: the frog name Hyla and other commentary on Specimen medicum (1768) of J. N. Laurenti, the ‘father of herpetology’.'' Archives of Natural History, 33(2), 241-266.

Santos-Barrera, G., Canseco-Márquez, L. (2004). Charadrahyla taeniopus. The IUCN Red List of Threatened Species 2004: e.T55671A11350853. http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T55671A11350853.en. Downloaded on 30 January 2017. amphibiaweb.org/species/972

Smith, H.M. and Taylor, E.H. (1948). ''An annotated checklist and key to the Amphibia of Mexico.'' United States National Museum Bulletin, 194, iv + 118.

Valdespino, C., Huerta-Peña, A. I., Pérez-Pacheco, A., von Osten, J. R. (2015). ''Persistent Organochlorine Pesticides in Two Hylidae Species from the La Antigua Watershed, Veracruz, Mexico.'' Bulletin of environmental contamination and toxicology, 94(1), 17-22.

Species Account Citation: AmphibiaWeb 2017 Charadrahyla taeniopus: Porthole Treefrog <https://amphibiaweb.org/species/972> University of California, Berkeley, CA, USA. Accessed Nov 27, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 27 Nov 2024.

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