Species New to Science

In an elevational gradient, the mountain top generally presents a reduced species diversity. However, it is there where we often find microendemic and quite often still undescribed species. That prediction is very common in underexplored Neotropical mountains, like those of the Caparaó National Park – a protected area that includes the highest peak of the Atlantic Forest, a megadiverse domain. Up in its top, we found a dwarf frog of the genus Physalaemus (Anura, Leptodactylidae, Leiuperinae), belonging to the P. signifer clade. After an integrative (morphological, bioacoustical, and genetic) analysis, we were able to describe it as a new species and found it to be sister to P. maculiventris. Due to its very restricted distribution at a site with extreme environmental conditions (which includes fires and frosts) and current instability in national environmental policy, we suggest this to be classified as an endangered species. A brief description of its natural history and the description of the species itself will now enable its proper conservation status categorization and the future planning for conservation actions.

Physalaemus sp. (aff. maculiventris) – Zornosa-Torres et al. 2020: 4–6, 12–13

Diagnosis: Physalaemus araxa sp. nov. is distinguishable from all congeneric species by having the following combination of character states: (1) presence of an arrow-shaped blotch on the dorsum of the body (Fig. 1A); (2) tarsal tubercle absent (Fig. 2D); (3) gular region and chest predominantly yellow in live individuals, pale cream in preserved specimens (Figs 1B, 3B–C); (4) belly with dark vermiculation pattern on a pale cream, slightly bluish background in live individuals (Figs 1B, 3C); (5) lack of aposematic coloration on ventral surface of hand and foot in live individuals (Fig. 3C); (6) intermediate size within the P. signifer clade (adult male SVL = 17.4–21.5 mm, Table 1); (7) presence of brown, divided, nuptial pad in males (Figs 1A, 2C); (8) supernumerary tubercles on foot absent (Fig. 2D); (9) tarsal fold absent (Fig. 2D); (10) texture of posterior region of belly and ventral surface of thigh smooth (Fig. 1B); (11) advertisement call duration from 69–304 ms (Table 2); (12) tadpole with a proportionally large body BL/TL = 0.39–0.43 (Table 4); (13) dextral vent tube (Fig. 6G); (14) dorsal and ventral fins of the same height (Fig. 6A, H; Table 4); (15) tail tip broadly rounded (Fig. 6A, H); (16) presence of submarginal papillae arranged in small rows; (17) A2 tooth row conspicuously longer than A1 (Fig. 6D); (18) absence of a dermal fold at the body-tail junction; (19) external margins of fins slightly convex (Fig. 6A, H); (20) gular region of tadpole convex.

Etymology: The specific epithet ʻaraxaʼ, is the combination of the Tupi-Guarani indigenous language words ʻaraʼ (meaning ʻworldʼ) and ʻeçaʼ (meaning ʻto seeʼ) meaning ʻthe first place where the sun can be seenʼ, in reference to the sunshine view on the top of hills (Chiaradia 2008). Also used to indicate the highest mountain in a landscape. That is the specific case of the type locality of Physalaemus araxa sp. nov., found on the mountaintop of the highest hill of the Atlantic forest.

Fernando Leal, Camila Zornosa-Torres, Guilherme Augusto-Alves, Simone Dena, Tiago Leite Pezzuti, Felipe Leite, Luciana Bolsoni Lourenço, Paulo Garcia and Luís Felipe Toledo. 2021. Head in the Clouds: A New Dwarf Frog Species of the Physalaemus signifer Clade (Leptodactylidae, Leiuperinae) from the Top of the Brazilian Atlantic Forest. European Journal of Taxonomy. 119-151. DOI: 10.5852/ejt.2021.764.1475