629 resultados para TOADS ANURA


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We report here the discovery of a new species of frog associated to the open areas of the highlands of the Parque Nacional da Serra dos Orgaos. The new species, Cycloramphus organensis is characterized by a unique skin texture, medium size ( maximum male and female SVL 26.4 mm and 33.3 mm respectively), dorsal surfaces uniformly brick red colored, uniformly areolate skin on dorsum, pupil horizontal, iris with a menisc on upper margin; no fleshy tubercles on eyelid, tympanic annulus concealed beneath skin, macroglands not visible externally, fingers and toes without fringes and webs; supernumerary palmar and plantar tubercles absent, nuptial spines absent. Despite the presence of an iris menisc, a character shared by frogs of both genera Cycloramphus and Zachaenus Cope, the combination of morphological characters is so unique that the allocation of the species to any of these genera remains ambiguous. Consequently, we used additional molecular-based phylogenetic analyses to ascertain the position of the new taxon. The new species proved to be embedded within the genus Cycloramphus.

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We describe the advertisement call, tadpole, karyotype, and additional information on the natural history of Cycloramphus lutzorum from southern Brazil. Sonograms were generated from digitally recorded calls. Tadpoles were collected in the field for description in the lab, and an adult was collected for karyotyping. Data on seasonal activity were gathered monthly from November 2005 to November 2007. All tadpoles (N = 21), juveniles (N = 18), and adults (N = 52) were found exclusively in streams. Reproduction, as identified by calling frogs, occurred from July through November. Frogs call all day long, but mostly at dusk, from rock crevices inside the stream edges near the splash zone. The call is short and loud, with 11 pulsed notes, of 491-641 ms, with a dominant frequency of 0.98-1.39 kHz. We describe the exotrophic and semiterrestrial tadpoles, always found in constantly humid vertical rock walls in the stream. Tadpoles of C. lutzorum are recognized by differences in labial tooth row formula, eye diameter, body shape, position of nares, and development of tail. Like congeneric species, the karyotype of C. lutzorum comprises 26 metacentric and submetacentric chromosomes. Cycloramphus lutzorum is restricted to and adapted for living in fast flowing streams, many of which are threatened by deforestation, pollution, and habitat loss. Therefore, we recommend the status of C. lutzorum be changed from its current ""Data Deficient"" to ""Near Threatened (NT)"" in the IUCN species red list.

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Analysis of the phylogenetic relationships among trypanosomes from vertebrates and invertebrates disclosed a new lineage of trypanosomes circulating among anurans and sand flies that share the same ecotopes in Brazilian Amazonia. This assemblage of closely related trypanosomes was determined by comparing whole SSU rDNA sequences of anuran trypanosomes from the Brazilian biomes of Amazonia, the Pantanal, and the Atlantic Forest and from Europe, North America, and Africa, and from trypanosomes of sand flies from Amazonia. Phylogenetic trees based on maximum likelihood and parsimony corroborated the positioning of all new anuran trypanosomes in the aquatic clade but did not support the monophyly of anuran trypanosomes. However, all analyses always supported four major clades (An01-04) of anuran trypanosomes. Clade An04 is composed of trypanosomes from exotic anurans. Isolates in clades An01 and An02 were from Brazilian frogs and toads captured in the three biomes studied, Amazonia, the Pantanal and the Atlantic Forest. Clade An01 contains mostly isolates from Hylidae whereas clade An02 comprises mostly isolates from Bufonidae; and clade An03 contains trypanosomes from sand flies and anurans of Bufonidae, Leptodactylidae, and Leiuperidae exclusively from Amazonia. To our knowledge, this is the first study describing morphological and growth features, and molecular phylogenetic affiliation of trypanosomes from anurans and phlebotomines, incriminating these flies as invertebrate hosts and probably also as important vectors of Amazonian terrestrial anuran trypanosomes.

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The locus coeruleus (LC) has been suggested as a CO2 chemoreceptor site in mammals. This nucleus is a mesencephalic structure of the amphibian brain and is probably homologous to the LC in mammals. There are no data available for the role of LC in the central chemoreception of amphibians. Thus the present study was designed to investigate whether LC of toads (Bufo schneideri) is a CO2/H+ chemoreceptor site. Fos immunoreactivity was used to verify whether the nucleus is activated by hypercarbia (5% CO2 in air). In addition, we assessed the role of noradrenergic LC neurons on respiratory and cardiovascular responses to hypercarbia by using 6-hydroxydopamine lesion. To further explore the role of LC in central chemosensitivity, we examined the effects of microinjection of solutions with different pH values (7.2, 7.4, 7.6, 7.8, and 8.0) into the nucleus. Our main findings were that 1) a marked increase in c-fos-positive cells in the LC was induced after 3 h of breathing a hypercarbic gas mixture; 2) chemical lesions in the LC attenuated the increase of the ventilatory response to hypercarbia but did not affect ventilation under resting conditions; and 3) microinjection with acid solutions (pH = 7.2, 7.4, and 7.6) into the LC elicited an increased ventilation, indicating that the LC of toads participates in the central chemoreception.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Anuran amphibians exhibit different patterns of energy substrate utilization that correlate with the intensity of vocal and locomotor activities. Given the remarkable differences among species in breeding and feeding strategies, and the different ways energy is used in the whole animal, the suggested correlations between calling and locomotor behavior and the level of energy substrates in the muscles responsible for such activities are more complex than previously reported. We explored the relationships between calling and locomotor behavior and energy supply to trunk and hindlimb muscles, respectively, within the ecologically diverse tree-frog genus Scinax. Specifically, we measured the relative amount of carbohydrates and lipids in these two groups of muscles, and in the liver of three species of Scinax that differ in vocal and locomotor performance, and compared our results with those of two other species for which comparable data are available. We also compared the contents of lipids and carbohydrates of conspecific males collected at the beginning and after 4 h of calling activity. The stomach content to potential feeding opportunities across species was also assessed in both groups of males. Scinax hiemalis and S. rizibilis exhibit comparatively low and episodic calling during long periods of activity whereas S. crospedospilus calls at higher rates over shorter periods. Male S. hiemalis had highest levels of trunk muscle glycogen followed by those of S. rizilbilis and S. crospedospilus, respectively. There was no correlation between total lipid content in trunk muscle and calling rate among different species, suggesting that other metabolic aspects may be responsible for the energetic support for vocal activity. The levels of lipids and carbohydrates in trunk and hindlimb muscles and liver of males collected at the beginning and 4 h into the calling period were similar across species, so the extent of energetic reserves does not appear to constrain vocal or locomotor activity. Finally, we found exceptionally high levels of carbohydrates and lipids in the liver of S. rizibilis, a trait perhaps related to a long and demanding breeding period.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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We describe adult morphology, advertisement call and some natural history traits of a new species of toad from the Pantanal, western Brazil. Rhinella paraguayensis sp. nov. belongs to the Rhinella margaritifera group, and is characterized by medium size, snout rounded in dorsal view, with a vertical apical ridge, supraorbital crests weakly developed, parietal crest not well developed, postorbital crest prominent, presence of a dorsolateral line of tubercles, tympanum evident, bony protrusions at angle of jaws, absence of vertebral apophyses and of projections on upper eyelids, and parotoid glands small. The new species is distinguished from other species of the group by geographic distribution and by the use of floating mats of vegetation as reproductive site.

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A new species of Proceratophrys cristiceps group is described from western Brazil. The new species is characterized by absence of prominent palpebral appendages and postocular swellings, males measuring 44.2 +/- 2.1 mm SVL (41.1-47.3 mm) and females 56.4 +/- 2.8 mm SVL (52.7-59.8 mm), snout rounded in dorsal, and obtuse in lateral views, dorsal skin uniformly rugose, with no elevated warts, and tympanum defined as a depression on the skin. The new species was found in Guapore river drainage, a highly impacted area due to the construction of water dams.

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Seventy specimens of Hypsiboas albopunctatus (Anura: Hylidae) were collected and surveyed for endoparasites in Brasilia, Brazil at the end of the rainy season (February and March) in 2005. Sixteen males (22.86%) were infected by Rhabdias sp., Aplectana sp., Cosmocerca sp., and Falcaustra mascula. Rhabdias sp., a lung parasite, presented the highest prevalence (8.57%), mean intensity of infestation (1.333), and mean abundance (0.114). Moreover, this is the first report of a rhabdiasid nematode in the Hylidae in Brazil. The intestinal parasites, Cosmocerca sp. and Aplectana sp., had a similar prevalence (5.71%), but the former presented a higher mean intensity of infestation and mean abundance. The behavior and food habits of amphibians are responsible for the differences in their helminthofauna, and this study presents four new records of nematodes in H. albopunctatus.

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A new species of the genus Amazophrynella is described from southern Amazonia, Brazil. The new species is characterized by its medium size for the genus (15.2-19.3 mm SVL in males, 20.2-25.7 mm SVL in females), snout rounded in dorsal view, acute in lateral view, presence of subrostral crest not converging anteriorly, finger I shorter than finger II, and by dorsal and ventral coloration. The reproductive behavior of the new species is similar to other Amazophrynella with pigmented and numerous eggs that are probably laid in temporary ponds.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Herein we report predation by the spider Lycosa erythrognatha on a newly metamorphosed anuran Rhinella ornata, observed in an aggregation of more than 50 individuals.