Description
Gastrotheca phelloderma is medium sized frog, with males up to 43.8 mm long and females up to 57.7 mm long. The head is wider than it is long and is as wide as the body. The snout is rounded dorsally and laterally. The body is moderately robust. The lips are flared and the top of the head is flat. The nostrils slightly bulge anteriorly, and are directed anteriolaterally. The oval tympanum is longer than it is wide. The distinct tympanic annulus and the tympanic membrane are smooth, and the supratympanic fold is weak. The dorsal surface of the head, body, and limbs has marked longitudinal ridges and a large number of warts and blisters. The skin on the ventral surface of the throat, belly and anterior half of the thighs is granular. The skin on the flanks is tubercular, while the posterior half of the thighs contain small, conical nodules. The rest of the skin is smooth. The fore limbs are long and robust and lack ulnar tubercles. The unwebbed hands are large with long fingers that have narrow, lateral fringes and end in round discs. The relative lengths of fingers are 1 > 2 < 4 < 3. The robust hind limbs lack calcar and tarsal tubercles, but have a distinct inner tarsal fold. The outer metatarsal tubercle is absent and the inner metatarsal tubercle is conical and ovoid. The toes, which are roughly one-third webbed, are long, with long narrow lateral fringes and end in round discs. Relative toe lengths are 1 < 2 < 5 < 3 <4 (Lehr and Catenazzi 2011).

Gastrotheca phelloderma can be distinguished from other species of Gastrotheca by the two dark brown paravertebral dorsal markings, showing pronounced longitudinal ridges and warts. Two other species of Gastrotheca, G. ossilaginis and G. phalarosa have range overlaps with G. phelloderma. Gastrotheca ossilaginis can be differentiated from G. phelloderma the presence of integumentary-cranial co-ossification, small round granulations on the skin of the dorsum and direct developing reproduction in G. ossilaginis. Gastrotheca phelloderma closely resembles, G. phalarosa but can be differentiated by the black ventrum with white spots and prominent dorsal pustules on G. phalarosa (Lehr and Catenazzi 2011).

Coloration in life is highly variable, but has only been described from photographs of two specimens. The male specimen has a cream venter with brown spots and paravertebral brown rows. The ventral surface of the hands, feet and pericloacal region is yellow. The female specimen has a greyish-tan dorsal surface with a reddish-brown perivertebral stripe on a pale grey background. The flanks are greyish-tan with some tiny dark brown spots. A small number of pale green flecks are found dorsally on the head and laterally below the eye. The dorsal surface of the extremities has reddish-brown patched surrounded by dark brown that is further surrounded by pale grey. The iris is reddish-brown with minute black reticulations and the pupil is ringed with bronze. In preservative, the dorsal and lateral ground color is dark grey with various greyish-brown markings. The flanks are dark grey with tiny black spots, the throat ranges from pale grey to white with some black spots on the edges. The chest, belly and extremities are cream ventrally, with the exception of the pale grey tarsus (Lehr and Catenazzi 2011).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Peru

View distribution map in BerkeleyMapper.

Gastrotheca phelloderma has been identified in two places (Pampa del Cuy and Alpamachay) in the Rio Abiseo National Park, which is located in the eastern Andes, in the San Martin region of Peru (Lehr and Catenazzi 2011).

Life History, Abundance, Activity, and Special Behaviors
Instead of direct development, as many species in the genus Gastrotheca do, this species produces tadpoles (Lehr and Catenazzi 2011). However, like other frogs in the genus, female G. phelloderma places eggs in a dorsal brood pouch where they hatch (del Pino et al 1975).

Trends and Threats
The status of G. phelloderma within the Rio Abiseo National Park is unknown. The fungus, Batrachochytrium dendrobatidis, which causes chytrid fungal infections in amphibians and has been linked to population declines in frogs in the Peruvian Andes, has been identified in Atelopus patazensis populations near the park. This poses a potential threat to G. phelloderma (Lehr and Catenazzi 2011).

Possible reasons for amphibian decline

General habitat alteration and loss
Disease

Comments
The species name Phelloderma comes from the Greek noun phellos, meaning cork or bark, and the noun derma, meaning skin. The name refers to the skin texture of the G. phelloderma, which is reminiscent of the bark of a tree such as oak (Lehr and Catenazzi 2011).

At the time of collection, one adult female specimen contained 49 embryos in the brood pouch (Lehr and Catenazzi 2011).

References

Lehr, E., and Catenazzi, A. (2011). ''A new species of marsupial frog (Anura: Hemiphractidae: Gastrotheca) from the Rio Abiseo National Park in Peru.'' Herpetologica, 67(4), 449-459.

del Pino, E. M., Galarza, M. L., de Albuja, C. M., and Humphries, A. A. Jr. (1975). ''The maternal pouch and development in the marsupial frog Gastrotheca riobambae (Fowler).'' The Biological Bulletin, 149, 480-491.

Species Account Citation: AmphibiaWeb 2013 Gastrotheca phelloderma <https://amphibiaweb.org/species/7736> University of California, Berkeley, CA, USA. Accessed Nov 21, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 21 Nov 2024.

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