Eupsophus migueli is a generally small frog, with a snout-vent length that ranges from 33.5 to 42.0 mm for both sexes. The head is as long as it wide and is 0.93 times narrower than the body. In the dorsal view, the snout is rounded to truncated and in the lateral view it is lightly acute to obtuse. The widely-set, laterally oriented nostrils are slightly prominent and closer to the eyes than the tip of the snout. The internarial region is slightly convex and less than a third of the head width. It has a sharp, straight canthus rostralis. The loreal region is flat. The large, prominent eyes are oriented laterally. The tympanum is round, visible, and slightly smaller than the eyes. The tympanic membrane is distinct (Formas 1978, Nuñez et al. 2012).
The skin is smooth on the surfaces of the head, dorsum, ventrum, and limbs. The frogs have well-developed dorsolateral folds that extend from the posterior corner of the eye to the above the forelimb. The forelimbs are slender. The outer palmar tubercle is almost rectangular and the inner palmar tubercle is oval; the two tubercles are of equal length. There are no palmar supernumerary tubercles. The slightly protruding fingertips are rounded and have relative lengths of III > IV > II > I with fingers I and II bearing nuptial pads. The subarticular tubercles are rounded with one on fingers I, II, and IV, and two subarticular tubercles on finger III. The hindlimbs are long and slender. When adpressed, the tibiotarsal articulation extends to the posterior edge of the eye. The inner metatarsal tubercle is well developed and ovoid. The outer metatarsal tubercle is a fourth of the size of the inner and conical shaped. The toes are thin, long, have rounded tips, and have a relative length of IV > V = III > II > I with delicate webbing between toes III and IV. The subarticular tubercles are rounded with one each on fingers I and II, two on fingers III and V, and three on fingers IV (Formas 1978, Nuñez et al. 2012).
Tadpoles have elliptical, slightly depressed bodies with a short sinestrally-oriented spiracle and total lengths between 18.4 - 19.6 mm. In both the lateral and dorsal profiles, the snout is somewhat truncated. The small, oval nostrils do not protrude and are located closer to anterior end of snout rather than eye. The internarial distance is smaller than the interorbital distance. The pupils are circular. The ventral oral disc is also circular and slightly emarginated with one row of marginal papillae. There are no intramarginal papillae. A rostral gap, without a mental gap, is present. Both upper and lower jaws are heavily keratinized. The labial tooth formula is 2(2)/2. The spiracle has an aperture that is half the eye diameter. The intestines are visible with poorly defined convolutions. The medially located vent is large, tubular, with a sharpened, longitudinal opening. The tail length is 0.70 times the length of the tadpole. Both the tail and the caudal fins are low and the tail width is 1.5 times the internarial distance. The tail curves vertically and has well-developed musculature. The tail tip is rounded (Nuñez et al. 2012).
From other species of the genus, E. migueli is distinguished by its coloration pattern and by having a notch in the lower part of the sternum, which is not present in other Chilean species of this genus (Formas 1978). Eupsophus migueli can be distinguished other species in the Eupsophus roseus group by its breeding season occurring in the winter, having terrestrial tadpoles, from its advertisement call, and by genetics (Nuñez et al. 2012). More specifically, E. migueli can be distinguished from E. roseus by its iris coloration and wine colored belly. Eupsophus roseus has a transparent belly and the upper half of the iris is orange (Formas 1978).
In life, dorsal coloration of adults ranges from reddish to pink. The flank coloration is white with yellow in the axillary and inguinal areas. The ventral coloration is white. Light-gray spots are present on the dorsal surface, light-gray bracelets are present on the extremities, small melanophores are distributed on ventral surface and the iris is yellow with black networking (Nuñez et al. 2012). In preservative, Nuñez et al. (2012) state that the color is similar to color in life. However, in the original description, Formas (1978) states that the dorsum is grayish black to olive green with two dark paravertebral areas that run to the tip of the head. Specimens may also have a dark mid-dorsal, hour-glass spot or a clean mid-dorsal line that extends from the snout to the vent. The ventral side is a dark wine color with irregular white spots. The iris has a bronze yellow top half and brown lower half (Formas 1978).
The body and tail of the tadpoles are unpigmented (Nuñez et al. 2012).
Individuals vary in coloration and pattern. Specimens may have either a green olive or grey dorsum in preservative. Specimens may also have a lighter vertebral line running from snout to vent or exhibit a dark hour-glass pattern, especially on those with an olive background. Spots on the venter also vary in size (Formas 1978).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Chile
The range of E. migueli is restricted to Valdivian rainforest on the western slopes of the coastal range of the Valdivia Province in Southern Chile between 50 m and 80 m in altitude. E. migueli can be found under logs and rotting trees in temperate Nothofagus forest (Formas 1978, Stuart et al. 2008, Veloso et al. 2010, Nuñez et al. 2012).
Life History, Abundance, Activity, and Special Behaviors
Eupsophus migueli is nocturnal and can be found year-round walking on the ground through vegetation. At night it can be found underneath rotted trees and logs. Males can also be found guarding nests during the breeding season (Nuñez et al. 2012).
Breeding is assumed to occur between May and August, as that is when males call the most and females are gravid (Nuñez et al. 2012).
The maximal activity for male calls was between May and August, which is winter in Chile. Male calls consist of one note, with an average duration of 336 ms. The range of the dominant frequency is between 1317 - 2098 Hz. Calls are high in harmonics (Nuñez et al. 2012).
Eggs are found between May and June and tadpoles between May and October. Eggs are laid in moist terrestrial nests made up of holes in the ground covered by logs and stones or in holes in trees up to a meter high, away from water. Clutches were composed of 17 – 30 eggs with a diameter of 5.5 – 5.7 mm that were easy to separate. Tadpoles complete their development in the nest and have male parental care (Nuñez et al. 2012).
E. migueli is described as a generalist carnivore. It feeds on insects, worms, plants and inorganic materials (Formas 1978).
Trends and Threats
Eupsophus migueli was once abundant in the 1970s. However, it is now listed as “Endangered” by the IUCN Red list because it is known from fewer than five locations and has an Extent of Occurrence that is less than 5000 km2. The species’ major threat is declining habitat quality from clear-cutting and cattle ranching. The species is not known from any protected areas (Stuart et al. 2008, Veloso et al. 2010).
Possible reasons for amphibian decline
General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
The species authority is: Formas, R. (1978). ''A new species of leptodactylid frog (Eupsophus) from the coastal range in Southern Chile.'' Studies on Neotropical Fauna and Environment , 13, 1-9.
Based on Bayesian analysis of morphology, mitochondrial sequences extending from 12 S to 16S rDNA, and nuclear DNA sequences from rhodopsin exon 1 and SINA, E. migueli is sister to E. insularis (Correa et al. 2017).
The species epithet “migueli” was given in honor of J. R. Formas’ son Miguel. J. R. Formas is the species authority of E. migueli (Formas 1978).
In 2012, a species thought to be Euposophus roseus, was determined to be distinct from E. roseus and was thus named E. altor, meaning “one who looks after or brings up its offspring” in Latin because males were observed near clutches of tadpoles (Nuñez et al. 2012). However, further analysis in 2017 revealed that E. altor was not genetically distinct from E. migueli and the two were combined. Because E. migueli was described first, that name had precedent over E. altor, which is now a junior synonym (Correa et al. 2017).
The karyotype of E. migueli is 2n=30 (Formas 1978, Nuñez et al. 2012).
Correa, C., Vásquez, D., Castro-Carrasco, C., Zúñigua-Reinoso, Á, Ortiz, J.C., Palma, R.E. (2017). ''Species delimitation in frogs from South American temperate forests: The case of Eupsophus, a taxonomically complex genus with high phenotypic variation.'' PLoS One , 12(8), e0181026.
Formas, R. (1978). ''A new species of leptodactylid frog ( Eupsophus) from the coastal range in Southern Chile.'' Studies on Neotropical Fauna and Environment , 13, 1-9.
Nuñez, José J., Felipe E. Rabanal, and J. Ramon Formas. ''Description of a New Species of Eupsophus (Amphibia: Neobatrachia) from the Valdivian Coastal Range, Southern Chile: An Integrative Taxonomic Approach.'' Zootaxa 3305 (2012): 53-68
Stuart, S., Hoffmann, M., Chanson, J., Cox, N., Berridge, R., Ramani, P., Young, B. (eds) (2008). Threatened Amphibians of the World. Lynx Edicions, IUCN, and Conservation International, Barcelona, Spain; Gland, Switzerland; and Arlington, Virginia, USA.
Veloso, A., Núñez, H., Formas, R. (2010). “Eupsophus migueli”. The IUCN Red List of Threatened Species 2010: e.T8376A12908703. http://dx.doi.org/10.2305/IUCN.UK.2010-2.RLTS.T8376A12908703.en. Downloaded on 09 August 2018.
Originally submitted by: Spencer J. Mennis, Anthony Gilbert, Mingna (Vicky) Zhuang (first posted 2011-06-23)
Edited by: Mingna (Vicky) Zhuang, Updated by Ann T. Chang (2018-08-09)
Species Account Citation: AmphibiaWeb 2018 Eupsophus migueli: Miguel's Toad <https://amphibiaweb.org/species/2629> University of California, Berkeley, CA, USA. Accessed Mar 28, 2023.
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Citation: AmphibiaWeb. 2023. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 28 Mar 2023.
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