AMPHIBIAWEB
Eleutherodactylus portoricensis
Forest Coqui
Subgenus: Eleutherodactylus
family: Eleutherodactylidae
subfamily: Eleutherodactylinae

© 2004 Luis J. Villanueva-Rivera (1 of 1)
Conservation Status (definitions)
IUCN (Red List) Status Endangered (EN)
CITES No CITES Listing
Other International Status None
National Status None
Regional Status None

 

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Description
Eleutherodactylus portoricensis is a medium-sized, stocky frog with females having a mean snout-vent length of 37.8 mm and males having a mean snout-vent length of 32.2 mm (Ríos López et al. 2015). The head is slightly wider than long and wider than the body. The canthus rostralis is well defined and rounded. The lores slope in a slight concave direction. The nostrils are closer to the snout than the eye by twice the length. The eye has a diameter equivalent to the distance between the eye and the nostril. There is a visible tympanum that is half the diameter of the eye and situated about one tympanum length from the eye. The skin of the dorsum is finely rugose and has a narrow raised line along the vertebrate while the belly and thigh are grainy. The skin is folded across the chest and a faint ventral disk that is seen by an impressed lateral line. When extended, the heel of the leg reaches the eye and when bent, the heels overlap. The toes and fingers of E. portoricensis have discs on their digits. The discs on the toes and fingers are approximately the same size. The length of the first finger is approximately the same as the second finger. As for the toes, the first and second toes are approximately the same in length. There is no webbing between the fingers or toes (Schmidt 1927).

Eleutherodactylus portoricensis can be differentiated from E. auriculatus by call and behavior. The former’s call sounds like a repeated “coqui” and the latter’s more closely resembles “chi-leén”. The former also breeds in bromeliads while the latter does not (Schmidt 1927).

In life the concealed parts of the thighs are reddish and immaculate. In preservative, the color of the frog is dark grey-brown. There is a light band starting from the canthus, over the eye to the tympanum, where it broadens and merges into the light colored belly (Schmidt 1927).

The gular region area of the females have no folded skin but the gular region of the male have folded skin, indicating a vocal sac (Ríos-López et al. 2015). There is also a high variability in coloration (Schmidt 1927).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Puerto Rico

 

View distribution map using BerkeleyMapper.
The species occur from Mountain of Luquillo in the east to the Mountains of Cayey in the southeast and to and Cordillera Central up to the Maricao municipality in western Puerto Rico. The elevation range of this species is from 180 m to 1,189 m above sea level. This species can be found in moist and cool habitats that include the montane forest (Ríos López et al 2015). It has not been recorded outside of mesic, upland broadleaf forests (Angulo 2008).

Life History, Abundance, Activity, and Special Behaviors
Eleutherodactylus portoricensis is terrestrial, and its habitat is mainly on the ground and understory vegetation in the Puerto Rico’s rainforests (Río-López et al. 2015). The species stays in forest litter during the day and climbs to vegetation at night where they are active (Drewry and Rand 1983). The species is known to climb up to 3 meters (Ríos-López et al. 2016).

The male E. portoricensis produce advertisement calls in their home range at night (Drewry and Rand 1983) from bushes and tree trunks (Angulo 2008). They have one to two types of notes per call with both lengths 50 - 80 msec. The note interval is 92 - 200 msec, and the dominant frequency of the two types of note is 1.5 - 1.8 and 2.2 - 3.0 kHz. The calls have a ramping pattern that the rate of calling increases to a peak and then calling stops suddenly (Drewry and Rand 1983).

Axillary amplexus was observed in a captive pair and in March 2016 a wild mating pair were found in a research tube set for the purpose of surveying frogs. During ovipositioning, the female of the species was observed using a reverse hind-leg grasp, positioning her legs above the males and holding on to his waist. This behavior was similar to the positioning observed in captivity and may help with internal fertilization, which is presumed in E. portoricensis. Hind-leg grasping and internal fertilization have also been documented in E. coqui, which is closely related and whose behavior E. portoricensis is presumed to be similar to (Ríos-López et al. 2016).

When disturbed during ovipositioning, both in the field and in captivity, males are known to consume newly laid eggs (Ríos-López et al. 2015 and 2016). Additionally, because females barely feed when gravid, if females are not removed from terrariums in captivity after laying eggs, they will consume the eggs or disturb males enough that the males will consume the eggs (Ríos-López et al. 2015).

Eleutherodactylus portoricensis lay clusters of eggs in bromeliads (Angulo 2008) a few inches above rainwater on the upper side of the lowest leaf petiole (Gitlin 1944). Multiple clusters have been found together in both the wild and in captivity (Gitlin 1944, Rio-Lopez et al. 2015). The species has direct development, with froglets emerging from eggs, and has male parental care (guarding) (Río-López et al. 2015). There are approximately 13 to 24 eggs per clutch; the diameter of the eggs is 5.1 mm on average (Joglar 1998). The development period for E. portoricensis varies from 22.3 days to 33.5 days (Río-López et al. 2015). Eggs can be found year round indicating an indefinite breeding season (Gitlin 1944).

Eleutherodactylus portoricensis has direct development and the limbs are formed within the egg. At temperatures ranging from 21 – 25.5oC, the hind-limbs emerged 6 hours before the forelimbs (Gitlin 1944).

In captivity, juveniles will reach adult size at 20 – 22 months but may not be sexually mature at that point. Wild individuals may take longer to reach adult size and maturity because of lack of resources(Ríos-López et al. 2015).

Eleutherodactylus portoricensis preys on invertebrates (mainly arthropods) such as ants, cockroaches, and cricket etc. with “sit-and-wait” strategy (Stewart and Woodbright 1996). The predators of juvenile E. portoricensis are invertebrates such as Sparassidae spiders, while reptiles and other anurans prey on adult E. portoricensis (Stewart and Woodbright 1996).

Trends and Threats

Eleutherodactylus portoricensis is rare and listed as “Endangered” by the IUCN Red List since 2004 (Angulo 2008). The population of E. portoricensis in El Yunque (Caribbean National Forest) has increased, but the population in Colorado Forest, which is about 200 m below the Elfin Forest of the El Yunque , has decreased (Burrowes et al. 2004). The main factors that associated with the decline of E. portoricensis are linked to chytrid fungal infections caused by Batrachochytrium dendrobatidis and the reduction of precipitation. This is a problem because the anurans lose water easily through their skin (Burrowes et al. 2004). The secondary causes for the declination of E. portoricensis includes pathogens and parasites such as acanthocephalan worms in stomachs and intestines, protozoan, and helminthic parasites (Burrowes et al. 2004). There is some habitat loss but not enough to explain the greater than 50% decline observed in this species (Angulo 2008).

Due to their dire situation, E. portoricensis are involved in an ex situ captive breeding project (Río-López et al. 2015).

Possible reasons for amphibian decline

Disease
Climate change, increased UVB or increased sensitivity to it, etc.

Comments
The species authority is: Schmidt, K. P. (1927). A New Tree-Frog from Porto Rico. American Museum Novitates, 279.

Eleutherodactylus portoricensis is closely related to E. antillensis and E. coqui (Ríos-López et al. 2015).

In 1871 Bello Espinosa described a Puerto Rican tree toad that natives called, "Coqui", and in 1876 Peters reported that Gundlach had found some eggs of E. coqui because Gundlach observations pointed it to being a coqui. However Sampson’s research on the embryology of the Jamaican E. luteolus and E. nubicola showed that the species they found were not E. coqui, but rather E. portoricensis. The name was proposed by Schmidt (1927) after investigating into the confusion between Puerto Rican species with E. martinicensis (Gitlin 1944).

The name "Eleutherodactylus" is derived from the Greek words for ‘free-toed’, by combining eleutheros (‘free, unbound’) and dactylos (‘finger, toe’) (Kenneth 2013).

Even though the species E. portoricensis is Endangered, its sister species, E. coqui are an invasive species in Hawaii, and are seen as pests (Kalnicky et al. 2014).

References

Angulo, A., 2008. Eleutherodactylus portoricensis. The IUCN Red List of Threatened Species 2008: e.T56875A11547757. http://dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T56875A11547757.en. Downloaded on 19 February 2017.

Burrowes, P. A., Joglar, R. L., and Green, D. E. (2004). ''Potential causes for amphibian declines in Puerto Rico.'' Herpetologica, 60, 141-154.

Drewry, G. E., Rand, A. S. (1983). ''Characteristics of an Acoustic Community: Puerto Rican Frogs of the Genus Eleutherodactylus.'' Copeia, 1983(4), 941-953.

Gitlin, D. (1944). ''The Development of Eleutherodactylus portoricensis.'' American Society of Ichthyologists and Herpetologists, 1944(2), 91-98.

Joglar, R. L. (1998). Los Coquíes de Puerto Rico: Su Historia Natural y Conservación. University of Puerto Rico Press, Puerto Rico.

Kalnicky, E. A., Brunson, M. W., Beard, K. H. (2014). ''A social–ecological systems approach to non-native species: Habituation and its effect on management of coqui frogs in Hawaii.'' Biological Conservation, 180, 187-195.

Ríos-López N., Agosto-Torres, E., Hernández-Muñíz, R. M., Cao, G. M. (2016). ''Natural History Notes on the Reproductive Biology of the Melodious Coqui, Eleutherodactylus wightmanae (Schmidt, 1920), the Whistling Coqui, E. cochranae (Grant, 1932), and the Mountain Coqui, E. portoricensis (Schmidt, 1927) (Anura: Eleutherodactylidae), from Puerto Rico.'' Life: The Excitement of Biology, 4(1), 3-10.

Ríos-López, N., Agosto-Torres, E., Hernández-Muñíz, R. M., Vicéns-López, C., Bernardi-Salinas, A., Tirado-Casillas, W. N., Flores-Rodríguez, Y. (2015). ''Conservation Efforts for the Puerto Rican Mountain Coqui (Anura: Eleutherodactylidae: Eleutherodactylidae portoricensis Schmidt, 1927): Reproductive Biology in Captivity.'' Life: The Excitement of Biology , 3(2), 61-82.

Schmidt, K.P. (1927). ''A New Tree-Frog from Porto Rico.'' American Museum Novitates, 279, 1-3.

Stewart, M. and Woolbright, L. (1996). ''The Food Web of a Tropical Rain Forest.'' Amphibians. D.P. Reagan and R.B. Waide, eds., University of Chicago Press, United States, 273-320.

Townsend, D., Stewart, M. (1994). ''Reproductive Ecology of the Puerto Rican Frog Eleutherodactylus coqui.'' Journal of Herpetology, 28(1), 34-40.



Written by Allen Huynh, Keth Pichta Pal, Ruoshi Huang (allhuynh AT ucdavis.edu, Kppal AT ucdavis.edu, ruohuang AT ucdavis.edu), University of California Davis
First submitted 2017-08-27
Edited by Ann T. Chang (2017-09-01)

Species Account Citation: AmphibiaWeb 2017 Eleutherodactylus portoricensis: Forest Coqui <http://amphibiaweb.org/species/3144> University of California, Berkeley, CA, USA. Accessed Oct 22, 2017.



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Citation: AmphibiaWeb. 2017. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 22 Oct 2017.

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