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93 result(s) for "Toledo, Luís F"
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anuran calling repertoire in the light of social context
Frogs are immediately associated to their conspicuous vocalizations emitted during the breeding season. Therefore, many scientists were inspired to study their acoustic communication. Nowadays, many types of calls are described and we felt the need of reviewing the terminology currently and historically applied. As a result, we proposed the classification of anuran vocalization into three major categories: reproductive, aggressive, and defensive calls. These categories are subdivided according to the social context of emission mostly reflecting also acoustic differences among call types. Some call types are here proposed to be synonymies of the mostly used and inclusive terms. We also suggest terminologies for basic bioacoustical analyses, mostly applied in call descriptions. Furthermore, we present cases of complex calls, including call gradation. Finally, based on novel data (such as an unusual case of juvenile vocalizations), we discuss situations in which it is difficult to classify call types, reflecting the need of experimental studies.
Seasonality, Environmental Factors, and Host Behavior Linked to Disease Risk in Stream-Dwelling Tadpoles
The aquatic pathogen Batrachochytrium dendrobatidis (Bd) can cause declines in amphibian populations and species extinctions worldwide. In tadpoles, epizootic events have not been reported; however, there is a possibility for rapid spread of disease in water. Here, we quantified Bd infection dynamics in tadpoles from two streams in the northeastern Atlantic forest of Brazil. Bd prevalence varied seasonally and increased during the rainy season. Aplastodiscus sibilatus and Proceratophrys renalis tadpoles were Bd positive in both seasons, whereas Agalychnis granulosa tadpoles were Bd positive only during the rainy season. Bd prevalence was higher in A. sibilatus than in A. granulosa and P. renalis. We found that larger individuals have a higher probability of being Bd positive, independent of the developmental stage. Moreover, we found that canopy cover, water flow, water temperature, water depth, and pH were associated with Bd prevalence. Our results highlight the fact that tadpoles can serve as pathogen reservoirs; therefore, monitoring anuran larvae populations in these habitats can enhance the impact assessment of this pathogen in biodiversity hot spots.
Fluorescence in amphibians and reptiles: new cases and insights
Fluorescence in amphibians and reptiles has emerged as a prominent study subject in recent years, with research focused on understanding its function and diversity. As the knowledge of fluorescence in vertebrates is still understudied, we surveyed amphibian and reptile species in montane and lowland Atlantic Forest sites to evaluate presence or absence of fluorescence. By randomly sampling species, we found evidence of fluorescence in amphibians of the genera Scinax, Brachycephalus and Hylodes, and reptiles of the genera Bothrops, Enyalius and Hemidactylus. Our findings increase the list of known species that may benefit from fluorescent patterns. Fluorescence was either ocular, dermal, or subdermal related to the skeleton or ossified dermal structures. Whether these species are able to see and interpret the different the patterns generated by fluorescent structures is yet to be discovered.
Tadpole, Oophagy, Advertisement Call, and Geographic Distribution of Aparasphenodon arapapa Pimenta, Napoli and Haddad 2009 (Anura, Hylidae)
The genus Aparasphenodon is poorly known. Of the four species, the larvae of only one have been described, and the advertisement calls of all taxa remain unknown. Here, we describe the tadpole, adult coloration, and advertisement calls of Aparasphenodon arapapa. We also provide data that extend its known distribution 170 km to the south, from the type locality in Ituberá to Una, Bahia, Brazil. In addition, we report larval morphology related to bromeligenous habitat specialization of tadpole and metamorph oophagy for the first time in the genus. The advertisement call is composed of one multipulsed note with mean duration of 150 ms. Whether the observed oophagy is obligatory or opportunistic remains unclear, suggesting that further studies are warranted. Our observations provide insight into the behavioral and morphological diversity in the genus Aparasphenodon, and may guide future studies of this unique group of anurans.
Effects of Season, Temperature, and Body Mass on the Standard Metabolic Rate of Tegu Lizards (Tupinambis merianae)
This study examined how the standard metabolic rate of tegu lizards, a species that undergoes large ontogenetic changes in body weight with associated changes in life‐history traits, is affected by changes in body mass, body temperature, season, and life‐history traits. We measured rates of oxygen consumption ( \\documentclass{aastex} \\usepackage{amsbsy} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{bm} \\usepackage{mathrsfs} \\usepackage{pifont} \\usepackage{stmaryrd} \\usepackage{textcomp} \\usepackage{portland,xspace} \\usepackage{amsmath,amsxtra} \\usepackage[OT2,OT1]{fontenc} \\newcommand\\cyr{ \\renewcommand\\rmdefault{wncyr} \\renewcommand\\sfdefault{wncyss} \\renewcommand\\encodingdefault{OT2} \\normalfont \\selectfont} \\DeclareTextFontCommand{\\textcyr}{\\cyr} \\pagestyle{empty} \\DeclareMathSizes{10}{9}{7}{6} \\begin{document} \\landscape $\\dot{\\mathrm{V}}\\textsc{$o$}_{2}$ \\end{document} ) in 90 individuals ranging in body mass from 10.4 g to 3.75 kg at three experimental temperatures (17°, 25°, and 30°C) over the four seasons. We found that standard metabolic rate scaled to the power of 0.84 of body mass at all experimental temperatures in all seasons and that thermal sensitivity of metabolism was relatively low ( \\documentclass{aastex} \\usepackage{amsbsy} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{bm} \\usepackage{mathrsfs} \\usepackage{pifont} \\usepackage{stmaryrd} \\usepackage{textcomp} \\usepackage{portland,xspace} \\usepackage{amsmath,amsxtra} \\usepackage[OT2,OT1]{fontenc} \\newcommand\\cyr{ \\renewcommand\\rmdefault{wncyr} \\renewcommand\\sfdefault{wncyss} \\renewcommand\\encodingdefault{OT2} \\normalfont \\selectfont} \\DeclareTextFontCommand{\\textcyr}{\\cyr} \\pagestyle{empty} \\DeclareMathSizes{10}{9}{7}{6} \\begin{document} \\landscape $\\mathrm{Q}\\,_{10}\\approx 2.0{\\mbox{--}} 2.5$ \\end{document} ) over the range from 17° to 30°C regardless of body size or season. Metabolic rates did vary seasonally, being higher in spring and summer than in autumn and winter at the same temperatures, and this was true regardless of animal size. Finally, in this study, the changes in life‐history traits that occurred ontogenetically were not accompanied by significant changes in metabolic rate.
Advertisement call of Scinax littoralis and S. angrensis (Amphibia: Anura: Hylidae), with notes on the reproductive activity of S. littoralis
Scinax littoralis and S. angrensis are poorly known Atlantic forest endemic species from the Scinax catharinae group, which is known from southern and southeastern Brazil. Herein, we describe the advertisement calls of these two species and compare them to other species within the S. catharinae group. Additionally, we provide information on breeding sites, and calling activity in S. littoralis. Advertisement calls of S. angrensis and S. littoralis are composed of multi-pulsed notes with multiple frequency bands and frequency modulation. Scinax littoralis has a higher minimum and maximum frequency, and lower dominant frequency than S. angrensis, while Scinax littoralis has a longer call. Scinax littoralis appears to be a habitat generalist, occurring from secondary to mature forests, and breeding both in temporary and in permanent ponds. Male S. littoralis were usually observed calling perched on shrub stems, and displayed satellite behavior when the male density was high.
Seasonal Changes in Daily Metabolic Patterns of Tegu Lizards (Tupinambis merianae) Placed in the Cold (17°C) and Dark
Oxygen consumption rate was measured continuously in young tegu lizardsTupinambis merianaeexposed to 4 d at 25°C followed by 7–10 d at 17°C in constant dark at five different times of the year. Under these conditions, circadian rhythms in the rate of oxygen consumption persisted for anywhere from 1 d to the entire 2 wk in different individuals in all seasons except the winter. We also saw a progressive decline in standard oxygen consumption rate (at highly variable rates in different individuals) to a very low rate that was seasonally independent (ranging from \\documentclass{aastex} \\usepackage{amsbsy} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{bm} \\usepackage{mathrsfs} \\usepackage{pifont} \\usepackage{stmaryrd} \\usepackage{textcomp} \\usepackage{portland,xspace} \\usepackage{amsmath,amsxtra} \\usepackage[OT2,OT1]{fontenc} \\newcommand\\cyr{ \\renewcommand\\rmdefault{wncyr} \\renewcommand\\sfdefault{wncyss} \\renewcommand\\encodingdefault{OT2} \\normalfont \\selectfont} \\DeclareTextFontCommand{\\textcyr}{\\cyr} \\pagestyle{empty} \\DeclareMathSizes{10}{9}{7}{6} \\begin{document} \\landscape $19.1\\pm 6.2$ \\end{document} to \\documentclass{aastex} \\usepackage{amsbsy} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{bm} \\usepackage{mathrsfs} \\usepackage{pifont} \\usepackage{stmaryrd} \\usepackage{textcomp} \\usepackage{portland,xspace} \\usepackage{amsmath,amsxtra} \\usepackage[OT2,OT1]{fontenc} \\newcommand\\cyr{ \\renewcommand\\rmdefault{wncyr} \\renewcommand\\sfdefault{wncyss} \\renewcommand\\encodingdefault{OT2} \\normalfont \\selectfont} \\DeclareTextFontCommand{\\textcyr}{\\cyr} \\pagestyle{empty} \\DeclareMathSizes{10}{9}{7}{6} \\begin{document} \\landscape $27.7\\pm 0.2$ \\end{document} mL kg−1h−1across seasons). Although this degree of reduction appeared to take longer to invoke when starting from higher metabolic rates, tegu lizards reduced their metabolism to the low rates seen in winter dormancy at all times of the year when given sufficient time in the cold and dark. In the spring and summer, tegus reduced their standard metabolic rate (SMR) by 80%–90% over the experimental run, but only roughly 20%–30% of the total fall was due to the reduction in temperature; 70%–80% of the total fall occurred at constant temperature. By autumn, when the starting SMR on the first night at 25°C was already reduced by 59%–81% (early and late autumn, respectively) from peak summer values, virtually all of the fall (63%–83%) in metabolism was due to the reduction in temperature. This suggests that the temperature‐independent reduction of metabolism was already in place by autumn before the tegus had entered winter dormancy.
Evaluation of the taxonomic status of populations assigned to Phyllomedusa hypochondrialis (Anura, Hylidae, Phyllomedusinae) based on molecular, chromosomal, and morphological approach
Doc number: 70 Abstract Background: The taxonomic and phylogenetic relationships of the genus Phyllomedusa have been amply discussed. The marked morphological similarities among some species hamper the reliable identification of specimens and may often lead to their incorrect taxonomic classification on the sole basis of morphological traits. Phenotypic variation was observed among populations assigned to either P. azurea or P. hypochondrialis . In order to evaluate whether the variation observed in populations assigned to P. hypochondrialis is related to that in genotypes, a cytogenetic analysis was combined with phylogenetic inferences based on mitochondrial and nuclear sequences. Results: The inter- and intra-population variation in the external morphology observed among the specimens analyzed in the present study do not reflect the phylogenetic relationships among populations. A monophyletic clade was recovered, grouping all the specimens identified as P. hypochondrialis and specimens assigned P. azurea from Minas Gerais state. This clade is characterized by conserved chromosomal morphology and a common C-banding pattern. Extensive variation in the nucleolar organizing region (NOR) was observed among populations, with four distinct NOR positions being recognized in the karyotypes. Intra-population polymorphism of the additional rDNA clusters observed in specimens from Barreiras, Bahia state, also highlights the marked genomic instability of the rDNA in the genome of this group. Based on the topology obtained in the phylogenetic analyses, the re-evaluation of the taxonomic status of the specimens from the southernmost population known in Brazil is recommended. Conclusions: The results of this study support the need for a thorough revision of the phenotypic features used to discriminate P. azurea and P. hypochondrialis . The phylogenetic data presented here also contribute to an extension of the geographic range of P. hypochondrialis , which is known to occur in the Amazon basin and neighboring areas of the Cerrado savanna, where it may be sympatric with P. azurea , within contact zones. The misidentification of specimens may have led to inconsistencies in the original definition of the geographic range of P. azurea . The variability observed in the NOR of P. hypochondrialis reinforces the conclusion that these sites represent hotspots of rearrangement. Intraspecific variation in the location of these sites is the result of constant rearrangements that are not detected by classical cytogenetic methods or are traits of an ancestral, polymorphic karyotype, which would not be phylogenetically informative for this group.
Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity
Rapid spread of disease is a hazard in our interconnected world. The chytrid fungus Batrachochytrium dendrobatidis was identified in amphibian populations about 20 years ago and has caused death and species extinction at a global scale. Scheele et al. found that the fungus has caused declines in amphibian populations everywhere except at its origin in Asia (see the Perspective by Greenberg and Palen). A majority of species and populations are still experiencing decline, but there is evidence of limited recovery in some species. The analysis also suggests some conditions that predict resilience
Warming drives ecological community changes linked to host-associated microbiome dysbiosis
Anthropogenic climate warming affects many biological systems, ranging in scale from microbiomes to biomes. In many animals, warming-related fitness depression appears more closely linked to changes in ecological community interactions than to direct thermal stress. This biotic community framework is commonly applied to warming studies at the scale of ecosystems but is rarely applied at the scale of microbiomes. Here, we used replicated bromeliad microecosystems to show warming effects on tadpole gut microbiome dysbiosis mediated through biotic community interactions. Warming shifted environmental bacteria and arthropod community composition, with linkages to changes in microbial recruitment that promoted dysbiosis and stunted tadpole growth. Tadpole growth was more strongly associated with cascading effects of warming on gut dysbiosis than with direct warming effects or indirect effects on food resources. These results suggest that assessing warming effects on animal health requires an ecological community perspective on microbiome structure and function.Replicated bromeliad microecosystems were used to examine warming-induced community shifts and changes to tadpole gut microbiome. Tadpole growth was more strongly associated with cascading effects of warming on gut dysbiosis than with direct warming effects or indirect effects on food resources.