140 resultados para Species description
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We present a description of the external morphology and internal oral features of the tadpole of Scinax catharinae and comparisons with the known tadpoles of the S. catharinae group. Two characters of the external morphology present some intraspecific variation: the row of submarginal papillae, which can be uniseriate or absent, and the tail tip, which can be large or small, truncated or not. That said, the tadpole of S. catharinae presents some distinguishing features that differentiate it from other tadpoles in the S. catharinae group: i) the marginal row of papillae with alternate disposition, ii) the spiracle opening on the midline of the body, iii) longest snout length, and iv) largest interorbital distance. The studied species were segregated into five ecomorphological guilds, characterized by external morphological features, tadpole habitat use and vegetation formation of species range. The taxonomy of the S. catharinae group is complex, due to the morphological similarities among the adults. Larval characters could help in the resolution of the taxonomic and phylogenetic complexities, since the morphological differences among the tadpoles in this group seem more conspicuous than those found among the adults.
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Alkaline metal doped organic - inorganic hybrids have potential applications in the field of portable energy sources. Attractive sol - gel derived urea cross-linked polyether, siloxane - PPO ( poly( propylene oxide)) hybrids doped with sodium salts ( NaClO4 and NaBF4) were examined by multi-spectroscopic approach that includes complex impedance, X-ray powder diffraction (XRPD), small angle X-ray scattering (SAXS), Si-29 and Na-23 magic-angle spinning nuclear magnetic resonance (NMR/MAS), Na K-edge X-ray absorption near edge structure (XANES) and Raman spectroscopies. The goals of this work were to determine which cation coordinating site of the host matrix ( ether oxygen atoms or carbonyl oxygen atoms) is active in each of the materials analyzed, its influence on the nanostructure of the samples and its relation with the thermal and electrical properties. The main conclusion derived from this study is that the NaBF4 salt has a much lower solubility in the hybrid matrix than the NaClO4 salt. Furthermore, the addition of a large amount of salt plays a major role in the hybrid nanostructure and electrical properties, modifying the PPO chain conformation, weakening or breaking the hydrogen bond of the polyether - urea associations and changing the polycondensation and aggregation processes involving the siloxane species.
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Internal larval oral anatomy was used to explore morphological diversity and its contribution to the systematics of the genera Aplastodiscus, Bokerinannohyla, and Hypsiboas, belonging to the tribe Cophomantini. Internal oral morphology was examined for tadpoles of 12 species. All species have a large pair of infralabial papillae on the buccal floor and other papillae on the prelingual region. In Aplastodiscus and Bokerinannohyla, the large infralabial papillae have digitiform secondary projections. The number and arrangement of the buccal floor papillae varies among species, but they are more numerous in Aplastodiscus and Bokerinannohyla. The arrangement of the postnarial papillae is variable, but in Aplastodiscus and Bokerinannohyla, they show a definite, inverted V-shape pattern. The lateral ridge papillae are more complex in larvae of Bokertnannohyla with long digitiform secondary projections. Tadpoles of only Aplastodiscus albofrenatus, Aplastodiscus eugenioi, and Bokerinannohyla luctuosa have papillae on the buccal roof arena and larvae of all species have lateral roof papillae except Hypsiboas albomarginatus and Hypsiboas cinerascens. Larvae of Aplastodiscus, Bokermannohyla, and Hypsiboas presumably share the presence of vacuities anterior to the internal nares; although this character state is clearly synapomorphic within hylids, it is still uncertain whether it is exclusive of these three genera or whether it is present in the other genera of the tribe Cophomantini (Hyloscirtus and Myersiohyla). The inclusion of internal oral anatomy characters, such as the narial vacuities, in systematic studies is certainly valuable because it will provide additional information toward the understanding of phylogenetic relationships.
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Specimens of Hyla nana and Hyla sanborni from a syntopic population were studied cytogenetically. These species are morphologically very similar and are frequently misidentified, confused with each other. Both species had a diploid chromosome number, 2n = 30. However, the karyotypes of H. nana and H. sanborni differed considerably from each other in the number of submetacentric and telocentric chromosomes. The two species also differed in their primary NOR-bearing chromosomes (metacentric pair 13 in H. nana and telocentric pair 12 in H. sanborni). Additional nucleolus organizer regions (NORs) were detected by Ag-NOR staining and FISH in chromosome pairs 1, 5, 6, 12, and 14 in seven specimens of H. nana. Thus, a total of six patterns of NOR were identified. These differences in karyotype and in NOR location allowed the unambiguous identification of syntopic individuals of the two species. However, the chromosomal morphology of both species differed from that reported for populations from other geographic regions, suggesting that a systematic reevaluation of this group of Hyla may be necessary.
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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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Kempnyia neotropica is the species with the widest distribution in this genus. In this work, samples collected in the states of Gois, Minas Gerais and So Paulo were analysed, confirming that all belong to a single species. The larva is described, the adult is redescribed and biological notes are presented.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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We redescribe Physalaemus spiniger and describe its tadpole and its reproductive modes. This species has the following three alternative reproductive modes: (1) foam nest on pond and feeding tadpoles in pond (the typical mode for the genus Physalaemus); (2) foam nest on humid places on the forest floor near a pond, and feeding tadpoles in pond; (3) foam nest on water accumulated on the axils of terrestrial bromeliads and feeding tadpoles in pond. These last two modes were not included in the reviews of reproductive modes in anurans. The vocalizations of P. spiniger are described and compared with the vocalizations of P. nanus, a sibling species.
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Cytogenetic studies were made on Brazilian Bufo: B. marinus, B. paracnemis, B. ictericus, B. rufus, B. arenarum, B. crucifer, Bufo granulosus, B. pygmaeus and B. margaritifer (= B. typhonius). All these species had a typical karyotype of 2n = 22. Species from the marinus and crucifer groups had NORs on Chromosome 7, species from the granulosus group had NORs on Chromosome 5, and B. margaritifer had NORs on Chromosome 10. The last two locations of NORs are described for the first time for the genus Bufo in South America.
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Two new species of Paratelmatobius are described from the Atlantic Forest of Sao Paulo State, southeastern Brazil. The vocalization, tadpole, and natural history of one new species are described. Natural history observations of P. poecilogaster are reported, including the description of a specialized reproductive mode. Diagnoses, measurements, figures, color in life, and distributional data for the species of Paratelmatobius are provided.
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The genus Leptodactylus provides an example among anurans in which there is an evident tendency toward terrestrial reproduction. Herein we describe a new reproductive mode for the frog Leptodactylus podicipinus, a member of the melanonotus group. This new reproductive mode represents one of the intermediate steps from the most aquatic to the most terrestrial modes reported in the genus. Three reproductive modes were previously recognized for the genus Leptodactylus. However, based on our data, and on several studies on Leptodactylus species that have been published since the last reviews, we propose a new classification, with the addition of two modes for the genus.
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Leptodactylus dantasi Bokermann is redescribed from adult specimens collected in Parque Nacional da Serra do Divisor, State of Acre, Brazil, near the border between the Brazilian state of Acre and Peru. We propose the inclusion of this species in the genus Hydrolaetare. A new diagnostic character observed for the genus is the presence of fringes of fingers, and fringes and webbing of toes, finely serrate; the serrate edge of the fringe and webbing can be keratinized in males, females, and subadults. Hydrolaetare dantasi (Bokermann) is characterized by robust body and limbs, a broad and depressed head, slightly shorter than wide, and long, pointed and basally webbed toes. Hydrolaetare dantasi differs from the only other species in this genus, Hydrolaetare schmidti (Cochran and Goin), mainly by having toes webbed basally (fully webbed in H. schmidti). The advertisement call of H. dantasi is composed of two components; an initial note produced by the impact of the vocal sac against the ground and a second note corresponding to a long whistle of ascending frequency. The initial note is a percussive sound and represents an unusual form of sound emission in anurans; the second note is a vocalization.
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We evaluated morphological and cytogenetic data for three animals similar to the species of deer previously described as the Small Red Brocket (Mazama bororo Duarte, 1996). We compared these animals with five M. americana, five M. nana and three hybrids between M. americana and M. nana. The M. bororo chromosomes can be standardized as follows : 8 group A chromosomes (large bi-armed) ; 2 group C chromosomes (small bi-armed) ; 4 group D chromosomes (large acrocentric) ; and 18 group E chromosomes (small acrocentric). There were great differences between this karyotype and those of M. nana and M. americana. With respect to external morphology, the animals in the present study had some similarities to M. americana and M. nana and great similarities with their hybrids. Most of the body measurements of M. bororo were significantly different from those of M. americana and M. nana, but similar to those of the hybrids. Mazama bororo is distributed in the last remnants of the Atlantic forest, extending from the southeastern part of the State of São Paulo to the northeastern part of the State of Paraná, Brazil. The rapid destruction of the Atlantic Forest requires urgent conservation measures for the species.
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There are many tales describing ferocious schools of piranha attacking humans, but there are few scientific data supporting such behavior. The very few documented instances of humans attacked and eaten by piranha schools include 3 that occurred after death by other causes (eg, heart failure and drowning). These predaceous fishes, however, do occasionally injure bathers and swimmers in lakes and rivers. The characteristic profile of most injuries is a single bite per victim, generally related to the fish defending its brood. This paper describes an outbreak of piranha bites in a dammed river portion in southeast Brazil. The outbreak was caused by the speckled piranha, Serrasalmus spilopleura, a widespread species which benefits from the growing tendency of damming rivers all over Brazil. This article focuses on the epidemiological and clinical aspects of the injuries, as well as on piranha biology, to gain a better understanding of the natural history of bite outbreaks.