Psyllophryne hermogenesi is one of two species belonging to the genus, both of which occur in the Atlantic forests of southeastern Brazil. This small frog, like other diminutive amphibians, has morphological reductions and losses in digits and other osteological elements (see Giaretta and Sawaya 1998 for figures). In life, this small anuran is brownish yellow or palebrown on the dorsum. The dorsal surface of the thigh may show a pale pink pattern. 40% of preserved specimens display narrow stripes that form a dark X on the dorsum. Some individuals have large symmetrically paired dark spots on the dorsum and/or sacrum region. Some have the dorsum of the limbs crossed with a gray stripe. A narrow vertebral stripe may be present, and in some specimens, lateral coloration is darker than dorsum. Ventral surfaces are pale gray with many brown spots. Belly has many intersperced glandular areas on a uniformly dark with white spotted background. The other congener, P. didactyla, differs by having its glands concentrated onto one belly area and thus creating a black spot. The head is wider than it is long, and in dorsal view the snout is rounded. Nostrils closer to tip of snout than to the eyes. Tympanum indistinct but visible. Anterior border of nostrils and inferior border of eys are grooved. First and fourth fingers vestigial, third larger than second. First toe is absent and the second is larger than fith and smaller than third. Skin is smooth or slightly granular on upper eyelid and nostril. Osterodermal plate on the body is absent (found in the sister genus Brachycephalus). The presence of a functional 5th toe in P. hermogenesi is unique within not only this genus, but also in other diminutive frogs of the genus Brachycephalus and Euparkarella (Lynch 1971).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Brazil
Known from 3 localities in the municipality of Ubatuba, Brazil: Picinguaba, Fazenda Capricornio, and Corcogado.
Life History, Abundance, Activity, and Special Behaviors
Males have an external vocal sac that extends from the gular region to midbelly. Females were frequently encountered with a bulk on one side of the body due to the presence of a single maturing oocyte.
Giaretta, A. A., and Sawaya, R. J. (1998). ''Second species of Psyllophryne (Anura: Brachycephalidae).'' Copeia, 1998(4), 985-987.
Lynch, J. D. (1971). ''Evolutionary relationship, osteology, and zoogeography of leptodactyloid frogs.'' Occasional Papers of the Museum of Natural History, University of Kansas, 53, 1-238.
Written by Raul E. Diaz (lissamphibia AT gmail.com), AWeb guy
First submitted 2004-06-04
Edited by Tate Tunstall (2004-09-01)
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