Description
Adelophryne maranguapensis is a small, slender frog described from two males, one female, and one juvenile. The snout to vent length of the adult males is 11.9 and 12.6 mm and the adult female is 17.4 mm. The head are notably longer than wide, as wide as or slightly wider than the adjacent part of the body. The shape of the snout is truncated and pointed in dorsal view and slightly projects beyond the mouth and rounded in a lateral profile. The vertically oval nostrils do not project and are directed laterally. The straight canthus rostralis is indistinct and rounded. The loreal region is steeply sloped to the upper lips. The lips do not flare. The distance between the eye and the nostril is smaller than the distance between the nostrils. The internarial and interorbital distances are about equal, but the internarial distance may be shorter. The flat to concave interorbital distance is 1.2 – 1.5 times the width of the upper eyelid. The eyes have horizontal, oval shaped pupils. The temporal region is vertical. The distance between eye and the tympanum is equal to or slightly larger than the diameter of the eye. The tympanum is rather small, about a third of the diameter of the eye. In some specimens the tympanum is distinct and in other specimens it is indistinct. They do not have supra-tympanic fold but does have skin covering the upper part of the of tympanum (Hoogmoed et al. 1994).

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

Country distribution from AmphibiaWeb's database: Brazil

View distribution map in BerkeleyMapper.

This species is endemic to the Serra de Maranguape in the State of Ceará, northeastern Brazil. It is found in steep primary and secondary Atlantic Forest with a range of less than 5,000 km ² and at elevations of 800 – 900 m asl (Hoogmoed et al. 1994, Silvano and Borges-Najosa 2004, de Lima et al. 2016).

Life History, Abundance, Activity, and Special Behaviors
Adelophryne maranguapensis is diurnal and found in terrestrial habitats, such as leaf litter (Silvano and Borges-Najosa 2004, de Lima et al. 2016).

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).

Reproduction of A. maranguapensis is prolonged, concentrated in the January - June rainy season. High humidity during the day is probably the main factor for the survival of egg masses. Viable clutches of A. maranguapensis were recorded only in the rainy season, with monthly rainfall > 150 mm, when differences between maximum and minimum relative humidity were very small (Cassiano-Lima et al. 2020).

The reproductive mode of A. maranguapensis is a subdivision of the arboreal eggs category stated as follows: ‘bromeligen periphytotelm eggs, with direct development’. Periphytotelmata, as proposed here, indicates that the plant forms a phytotelm environment, but makes it clear that the eggs are not deposited into the water (Cassiano-Lima et al. 2020).

Females have a clutch of 3 - 8 eggs, which are deposited near water in the axils of bromeliad leaves where moisture collects (Cassiano-Lima et al. 2011). 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).

Egg clutches of A. maranguapensis were found predominantly in the bromeliads Guzmania lingulata and Vriesea cearensis. However, transects indicate that there is no specific selection and suggest that A. maranguapensis uses the most abundant bromeliad species in each locality (Cassiano-Lima et al. 2020).

Female A. maranguapensis have parental care of egg attendance only until formation of the gel layer in all the eggs in the clutch (Cassiano-Lima et al. 2020).

Trends and Threats
This rare, endemic species is listed as “Endangered” on the IUCN Red and threatened due to its already small range and human impacts (Silvano and Borges-Najosa 2004, de Lima et al. 2016). Heavy habitat disruption is caused by human settlement, logging, and agriculture. Although the species can be locally abundant, this species does not occur on any protected area and needs conservation actions to ensure its survival (Silvano and Borges-Najosa 2004).

Comments

The genus name, Adelophryne, translates to “invisible frog” (Hedges et al. 2008).

References

Cassiano-Lima, D., Borges-Nojosa, D. M., Cascon, P., Cechin, S. Z. (2011). "The reproductive mode of Adelophryne maranguapensis Hoogmoed, Borges & Cascon, 1994, (Anura, Eleutherodactylidae) an endemic and threatened species from Atlantic Forest remnants in northern Brazil." North-Western Journal of Zoology, 7(1), 92-97. [link]

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]

Cassiano-Lima, D., Lima, A. V. P., Fortunato, M. E. M., de Sousa, T. A., de Castro, D. P., Borges-Nojosa, D. M., Cechin, S. Z. (2020). "Reproductive biology of direct developing and threatened frog Adelophryne maranguapensis (Anura, Eleutherodactylidae) reveals a cryptic reproductive mode for anurans and the first record of parental care for the genus." Journal of Natural History, 54:27-28, 1721-1733 [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]

Species Account Citation: AmphibiaWeb 2022 Adelophryne maranguapensis <https://amphibiaweb.org/species/5713> University of California, Berkeley, CA, USA. Accessed Nov 26, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 26 Nov 2024.

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