A new miniaturized frog of the genus Brachycephalus (Anura: Brachycephalidae) is described from Morro Santo Anjo in the municipality of Massaranduba, Santa Catarina, southern Brazil. Specimens were collected from the leaf litter between 470 and 540 above sea level. The new species is distinguished from all its congeners by the combination of the following characters: (1) body robust and bufoniform; (2) size snout-vent length 9.9–11.7 mm for males and 10.0–12.9 mm for females; (3) smooth dorsum; (4) general color (in life) orange with white dots and stripe in the middle of the head and along its vertebral column; (5) iris completely black; (6) advertisement call composed of note groups; (7) isolated notes with 1–3 pulses; and (8) short isolated notes (0.002–0.027 s). An estimate of the male density of the new species is also presented. Phylogenetic information indicates that the new species is part of the southernmost clade of Brachycephalus, which includes Brachycephalus fuscolineatus, B. albolineatus, and B. boticario. The severe anthropogenic impacts in and around the type locality indicate that immediate actions should be taken to ensure the long-term preservation of the new species.

Microcystins (MCs) are hepatotoxins that have been considered to be a worldwide problem due the effects that they can cause to environmental and human health systems. The Iraí Reservoir, located in the South of Brazil, is used as a water supply and MCs concentrations have been reported in this ecosystem. This study aimed to determine the MCs concentrations in the Iraí Reservoir and to evaluate the MCs depuration time and the health of Geophagus brasiliensis using biomarkers. Water and fish samples were collected in the Iraí Reservoir from August 2015 to May 2016. Phytoplankton and chemical analyses were conducted using water samples and the fish were divided into two groups; the Immediate Group (IMM) and the Depuration Group (DEP). In the IMM group, the blood, liver, muscle, brain and gills were collected, in order to evaluate the genotoxic, biochemical and chemical biomarkers. The DEP group was used in the depuration experiment for 90 days, and after this period the fish were submitted to the same procedure as the IMM group. Our results suggested that fish accumulated MCs and it may have caused oxidative stress, neurotoxicity and molecular damage. Furthermore, MCs concentrations increased during the depuration time and it resulted in molecular damage over the first 30 days. After 90 days, the recovery of the antioxidant system occurred. The depuration started on the 15th day, however, the toxins were still present in the samples. Therefore, the effects and the persistence of MCs are a risk to environmental systems and human health.

In a series of papers starting in the early 1980s, Toft proposed a general scenario to explain dietary evolution in leaf litter anurans in which species would “form a continuum from those that specialize on ants and mites, through generalists, to species that avoid ants and mites”, and these differences would in turn correlate with foraging strategies, morphology, and defense mechanisms. In this study, we reassess this hypothesis using a global dataset on the dietary composition of 120 anuran species. Surprisingly, we found that the relative contribution of ants and mites in anuran diets were largely orthogonal to one another. Moreover, we did not find evidence for the continuum of dietary composition envisioned by Toft. These results suggest that, although ants and mites have played a major role in the evolution of aposematic species, the trends found in those species might not be directly extrapolated to all leaf litter anurans.

The mineralized dermal layer (MDL) is found in most terrestrial anurans. Its thickness represents on average up to 8% of that of the entire skin. It has been proposed that it may reduce body water loss, act on homeostasis, support skin structure, or conversely, it may be a currently functionless trait constrained by groups' evolutionary history. We described the MDL morphology of 11 Brachycephalus species, terrestrial, miniaturized and microendemic anurans, and tested for its relationship with climate of higher latitude regions of the Atlantic Rainforest of Brazil. All species presented MDL, described with two distinct morphological patterns: homogeneous or heterogeneous MDL, the latter distinguishable by MDL with dorsal or lateral expansion, sometimes up to the limit of the epidermis and comprising up to 50% of the thicknesses of the entire skin. Climate differed between locations by MDL morphological group, less rainy or seasonally less rainy where species with heterogeneous MDL occur. Our results indicate that the abundance of calcium in MDL and its heterogeneous condition suggest its adaptive function in reduce water loss. Such adaptations in anurans in very humid highlands reinforce the mountains' propensity for rapid loss of humidity, demystifying them as an extremely abundant source of water. This is the third study that tested the relationship between the MDL morphology and the environment where species occur and the first that correlated this structure with the climate of anurans of the same habit and distributed in a single habitat, the Atlantic Rainforest.

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