A Second Species of Trachycephalus Tschudi (Anura: Hylidae) with a Single Vocal Sac from the Brazilian Amazon
A new species of Trachycephalus from the Brazilian Amazon Rain Forest, morphologically similar to T. hadroceps (Duellman and Hoogmoed), is described. This new species is characterized by having the skin not co-ossified with the skull; skin on dorsum bearing many low and medium round tubercles; a vocal sac not externally visible; well-developed paratoid gland; snout rounded in profile; third finger disc almost the same size of the eye; absence of tarsal fold; iris pinkish-beige with a horizontal dark gray bar; dorsal color pattern in life light brownish-orange with scattered brown dots. Trachycephalus hadroceps is restricted to the left margin (north) of the Amazon River, in the Guiana Shield, and possibly in the adjacent Brazilian Amazon Rain Forest, and the new species occurs on the right margin (south) of the Amazon River. It is a canopy treefrog, which probably uses treeholes filled with water as breeding sites.
Dorsal (A) and ventral (B) views of the holotype of Trachycephalus helioi, new species, MPEG 32558, SVL 57.6 mm.
Dorsal (A) and lateral (B) views of the head, hand (C) and foot (D) of the holotype of Trachycephalus helioi, new species, MPEG 32558. General scale = 10 mm.
(A) Living holotype of Trachycephalus helioi, new species, MPEG 32558, Municipality of Juruti, Pará State, and (B) specimen of T. hadroceps, Guyana, unvouchered photo by Walter Hödl.
(A) Map with known geographic distribution of Trachycephalus helioi, new species, and T. hadroceps in the Amazonian Rain Forest and Guyana Shield. Captions for Trachycephalus hadroceps: holotype = open circle, literature records = dashed squares; captions for T. helioi, new species: holotype = closed circle, paratypes = triangles. (B) Detailed map of the geographic distribution of T. helioi, new species. Captions: holotype = closed circle, paratypes = triangles, open squares = sound recordings.
Contributor Notes
Associate Editor: B. Stuart.