The hands have undivided, round, flat outer and a slightly smaller, round inner metacarpal tubercle. The relative finger lengths are I < II < IV < III and the fingers have a phalangeal formula of 2 – 2 – 3 - 3. The terminal phalanges are T-shaped. Their fingers are depressed with small pads on the underside with a formula of 1 – 1 – 2 – 2. There are no pads under the ultimate phalanges. Their digits do have obvious discs with circumferential groove that are interrupted by an asymmetrical pointed to nearly rounded tip. The tip of finger I has a small disc, slightly wider than adjacent phalange, tips of fingers II - IV have larger discs. The disc on finger III is the largest, being distinctly wider than adjacent phalange. Their fingers and toes are free from webbing (Hoogmoed et al. 1994).
When the hindlimb is adpressed along the body, the heel reaches to the eye or the region between the eye and the snout. When the hind limbs are held at right angles to the body, the heels touch. The tibia is about half the snout-vent length. The tarsus is smooth and does not have a ridge or tubercle. The inner metatarsal tubercle is distinct, oval, and flat. The outer metatarsal tubercle is smaller, round, and conical. The relative toe lengths are I < II < V < III < IV with a phalangeal formula of 2 – 2 – 3 – 4 – 3 and T-shaped terminal phalanges. The flat sub-digital pads have a pattern of 1 – 1 – 2 – 3 – 2, but there are no subarticular tubercles on the toes. The toes are cylindrical at their ends but flattened closer to the palm. They are not webbed. The tips of the toes expand into distinct round discs with asymmetrically pointed tips that are much wider than the adjacent phalanges. Toe V has a small disc with a pointed or rounded tip. Like the fingers, the discs have a circumferential groove that is interrupted by the tip (Hoogmoed et al. 1994).
The skin on their flanks, ventrum, throat, and limbs are all smooth. The skin on their backs, dorsolateral area, is slightly pustulous. There are a few indistinct grandules located between the tympanum and the insertion of the forearm. Male A. maranguapensis do not have longitudinal folds on their throats. Discoidal folds are absent from this species. Males have vocal slits near the corner of their mouth, and with a subgular vocal sac which is not very visible (Hoogmoed et al. 1994).
Among Adelophryne, there is a split between species with two phalanges in their fourth finger and those with three. Adelophryne maranguapensis has three, which differentiates it from A. adiastola and A. pachydactyla. Adelophryne maranguapensis lacks subarticular tubercles on their toes, but does have sub-digital pads, and has a distance between the eye and the tympanum that is about equal to the eye diameter that distinguishes it from A. baturitensis. From A. gutturosa, a pointed to rounded snout in the lateral profile, discs that are much larger than the adjacent phalange, and a transverse flap above the cloaca that ventrally opens in A. maranguapensis differentiate the two (Hoogmoed et al. 1994).
In life, the dorsum has a mostly dark brown to reddish brown hourglass-shaped central marking. The dorsolateral area is usually light brown to beige. They have a dark brown lateral band. Their limbs are light in color with dark transverse bands. The underside of the limbs can range from purple to flesh colored with random purple spots to dark brown with lighter spots. Their throat, chest, and belly also range in color, from purple with lighter spots to dark brown with lighter spots (Hoogmoed et al. 1994).
In preservative, there is a dark crescent or V-shaped marking between the eyes. There is an indistinct brown canthal stripe. The sides of the head are brown, but variegated with lighter markings. The dark brown central hourglass-shaped pattern is retained and often has darker brown spots along its margin. The dorsolateral to upper lateral areas of the back are light colored and ventrally bordered by a distinct dark brown lateral band that extends from the eye, over the tympanum, obliquely crosses the flanks and ends at the groin. The patterning of the flanks below this lateral band is dark brown with white spots. At the forelimb insertion there is a dark brown spot on the anterior side on the upper arm. The forearm has a dark transverse band boarded by two light bands. There are a pair of dark inguinal spots that are continuous with the two dark brown transverse band on the thigh. There are also two dark bands on the shanks, tarsus, and feet. There are white spots over all the articulations of the toes and transverse lines over the ultimate articulations of the fingers and toes. The ventrum of the body and limbs are dark brown with white spots (Hoogmoed et al. 1994).
Variations includes the ranges in color. In life, these species can range from a purplish hue to a brown hue and in preservative they can be darker or lighter in background color (Hoogmoed et al. 1994).
Distribution and Habitat
Life History, Abundance, Activity, and Special Behaviors
The advertisement call of A. maranguapensis consists of 5 to 8 multi-pulse notes, with a note duration of 0.663 – 1.075 s and a frequency ranging from 4483.64 - 4830.67 Hz. The interval between notes was 0.092 – 0.484 s with a repetition rate of 6.45–5.55 notes (Cassiano-Lima et al. 2014).
Females have a clutch of 6 - 8 eggs, which are deposited near water in the axils of bromeliad leaves where moisture collects. The embryos are white and enveloped in a thick, transparent, sticky jelly. As the embryos develop, they start resembling the adults and are visible through the transparent jelly. The species reproduces by direct development and will hatch into froglets that are about 4.5 mm in length with similar morphology to adults (de Lima et al. 2016).
Some observations of females guarding their clutch suggest parental care is provided by the females (de Lima et al. 2016).
Trends and Threats
The genus name, Adelophryne, translates to “invisible frog” (Hedges et al. 2008).
Cassiano-Lima, D., Borges-Nojosa, D. M., Cechin, S. Z (2014). "The advertisement call of Adelophryne maranguapensis (Anura, Eleutherodactylidae)." Zootaxa , 3835(2), 299-300. [link]
Hedges, S. B., Duellman, W. E., Heinicke, M. P. (2008). ''New World direct-developing frogs (Anura: Terrarana): Molecular phylogeny, classification, biogeography, and conservation.'' Zootaxa, 1737, 1-182.
Hoogmoed, M.S., Borges, D.M., Cascon, P. (1994). "Three new species of the genus Adelophryne (Amphibia: Anura: Leptodactylidae) from Northeastern Brazil, with remarks on the other species of the genus." Zoologische Mededelingen, 68, 271-300. [link]
Silvano, D., Borges-Najosa, D.M. (2004). "Adelophryne maranguapensis." The IUCN Red List of Threatened Species 2004: http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T56302A11452757.en.
de Lima, A.V.P., Reis, A.H., Amado, N.G., Cassiano-Lima, D., Borges-Nojosa, D.M., Oria, R.B., Abreu, J.G. (2016). "Developmental aspects of the direct-developing frog Adelophryne maranguapensis." Genesis, 54(5), 257-271. [link]
Description by: Carissa Ortega (updated 2021-04-03)
Distribution by: Carissa Ortega (updated 2021-04-03)
Life history by: Carissa Ortega (updated 2021-04-03)
Trends and threats by: Carissa Ortega (updated 2021-04-03)
Comments by: Carissa Ortega (updated 2021-04-03)
Edited by: Ann T. Chang (2021-04-03)
Species Account Citation: AmphibiaWeb 2021 Adelophryne maranguapensis <https://amphibiaweb.org/species/5713> University of California, Berkeley, CA, USA. Accessed Apr 11, 2021.
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Citation: AmphibiaWeb. 2021. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 11 Apr 2021.
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