A new species of Brachycephalus (Anura: Brachycephali­dae) from Serra do Tabuleiro, Southern Brazil

Abstract

The number of described species of Brachycephalus has rapidly increased in the last decade (n = 22, which represents 56% of the total). Species of the genus Brachycephalus are mostly distributed in isolated mountaintops from Bahia (northeastern Brazil) to Santa Catarina states (southern Brazil), each one occupying only one or a few adjacent mountaintops. Herein, we described a new species of Brachycephalus of the B. pernix group, from Serra do Tabuleiro in Santa Catarina state, which also represents the southernmost known species. The new species can be distinguished from its congeners by a combination of characters, including the following: (1) “bufoniform” body; (2) small adult SVL: 9.57–11.10 mm for males and 10.88–12.70 mm for females; (3) head proportionally small (HL/SVL 19–28%) and eye proportionally large (ED/HL 36–56%); (4) dorsum texture rough; (5) snout shape rounded in dorsal and lateral views; (6) general dorsal body color olive green with head, arms and legs yellow-orangish scattered with olive green, and an orangish vertebral stripe spotted with white and brown colors; (7) skull and skeleton without hyperossification; (8) frontoparietal and sphenethmoid not fused; (9) advertisement with one or two high-frequency notes (6,115–6,562 Hz), and 2–4 pulses per note. The type locality is adjacent to Parque Estadual da Serra do Tabuleiro, a protected area, but we observed various agricultural activities in this locality, including the presence of exotic plants, which can change the amount and the quality of leaf litter, somehow compromising the population of the new species. Another aggravating factor is that the municipality of São Bonifácio has conflicts over land use with irregular occupation and unfinished expropriation processes in Parque Estadual da Serra do Tabuleiro. Considering that Brachycephalus sp. nov. is probably a mountaintop microendemic species, it is paramount that future studies quantifying the new species’ full distribution and evaluating population trends to accurately assess its conservation status.