41 resultados para terrestrial turtles
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In order to help elucidate the evolution of alpha-globins, the complete cDNA and amino acid sequences of Geochelone carbonaria and Geochelone denticulata land turtles alpha-D chains have been described. In G. carbonaria, the cDNA is 539 bp with ATG start codon located at position 46, TGA stop codon at position 469 and AATAAA polyadenylation signal at position 520. In G. denticulata, the cDNA is 536 bp with ATG start codon located at position 46, TGA stop codon at position 469 and AATAAA polyadenylation signal at position 517. Both cDNAs codify 141 amino acid residues, differing from each other in only four amino acid residues. When comparing with human Hb alpha-chain, alterations in important regions can be noted: alpha110 Ala-Gly, alpha114 Pro-Gly, alpha117 Phe-Tyr and alpha122 His-Gln. There is a high homology between the amino acids of these turtles when compared with chicken alpha-D chains, progressively decreasing when compared with human, crocodile, snake, frog and fish alpha-chains. Phylogenetic analysis of alpha-D chains shows that those of turtles are closer to those of birds than to snakes and lizards. (C) 2002 Elsevier B.V. All rights reserved.
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Flowering phenology, breeding system and nectary structure of Corymborkis flava (Sw.) Kuntze were studied in a fragment of the Atlantic Forest in south-eastern Brazil. The flowering period extended from March (end of rainy season) to early June and seed dispersal occurred from June to September (dry season). Flowering peak occurred mainly in April, with up to 34 open flowers per plant being observed. The yellow, odourless and tubular flowers lasted similar to 7.8 days. The flowers present a perigonal nectary located in the basal lateral parts of the labellum; this is the first report on the nectary location and characterisation in the Tropidieae tribe. At the pre-anthesis stage, cells of both secretory parenchyma and epidermis of the nectary are filled with compound amyloplasts. However, starch grains were not observed in these tissues in senescent flowers, indicating that these starch grains are hydrolysed and used as source of sugars for nectar production. The nectar accumulates between the cuticle and the outer periclinal wall of the epidermal cells before. owing out into the nectar chamber. C. flava is a self-compatible species and spontaneous self-pollination does not occur because of hercogamy. The high pollinia removal (0.80) and insertion (0.82) per flower, as well as the high natural fruit-set indicate an efficient natural pollination system. The present study contributes for the knowledge of the diversity of reproductive strategies and nectary structures in Orchidaceae.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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This study shows for the first time that terrestrial tank bromeliads from Brazilian restinga can act as natural traps for dispersed palm Euterpe edulis seeds. Such bromeliads, which are shade intolerant, gain benefits by limiting palm recruitment since they hinder canopy formation and, consequently, increase luminosity over its aggregates.
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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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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This study examines the ecology of a population of Geoffroy's side-necked turtle Phrynops geoffroanus inhabiting a polluted urban river in Ribeirão Preto city, São Paulo state, south-eastern Brazil. Adult turtles fed mainly on Chironomidae larvae and pupae (Chironomus cf. plumosus, 100% of occurrence frequency) and domestic waste, but they also consumed terrestrial items (cockroach, snails) and carrion. Juvenile turtles showed more feeding diversity than the adults and exhibited a trend for predation on Chironomidae pupae, but this is not reflected in resource partitioning. The elevated number of turtles (170-230 turtles/ha of river) and biomass (255-345 kg/ha of river) inhabiting this urban river is probably the result of the abundance of sewage and organic waste produced by humans, the absence of predators, and increased availability of nesting areas. Such factors convert this area into an environment highly advantageous for the survival of Geoffroy's side-necked turtle.
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The reptile fauna in the municipality of São Paulo is well sampled due to intensive collection in the last 100 years. In the present work we provide a checklist of reptile species in São Paulo municipality based on preserved specimens in scientific collections. The reptile fauna was also characterized by three ecological parameters: habitat use, substrate use, and diet. We recorded a total of 97 reptile species (two turtles, one crocodilian, 19 lizards, seven amphisbaenians, and 68 snakes). Approximately 70% of the lizards and 40% of the snakes are typical of forest habitats of the Serra do Mar mountain range. Other squamates are typical of open formations that occur mainly on inland Cerrado habitats. All turtles and the crocodilian are associated to riparian habitats. Approximately 63% of the lizards are predominantly terrestrial, and the remaining species are arboreal. Most species of snakes are terrestrial (38%) or subterranean/criptozoic (25%) whereas a smaller proportion are arboreal (18%) or aquatic (9%). Lizards feed upon arthropods. Almost 50% of the snake species are specialized or feed mainly upon anuran amphibians. Other important items consumed by snakes are mammals (24%), lizards (18%), subterranean vertebrates (10%), and invertebrates (earthworms, mollusks and arthropods; 15%). A total of 51 reptile species have not been recorded for the last six years. Probably many of these species are extinct in the region due the intense local urbanization and habitat loss. The survey of species collected in São Paulo municipality and received in the Instituto Butantan in recent years allowed the identification of 10 lizards at least 42 snake species already occurring in the region. The high species richness of the original fauna seems related to the geographic location of the municipality, in a contact zone between forested areas of the Atlantic Forest (ombrophilous forest) and open formations (savannas, high-altitude grassland). Thus, the original habitat composition probably allowed sympatry among different species pools typical of both open and forested formations. The extant snake fauna recorded in the last three years indicates a higher loss of the species in open formations when compared to the forested areas.
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Physalaemus crombiei is a small foam-nesting frog endemic to the Atlantic forest. It is a member of the P. signifer group known only from its type locality in Santa Teresa, State of Espírito Santo, and from another locality in the State of Bahia, Brazil. Most Physalaemus species are aquatic breeders, and species in the P. signifer group are the only ones exhibiting a tendency toward terrestrial reproduction in the genus. Here we describe the reproductive period, breeding site and reproductive modes of P. crombiei from a third population in the Atlantic forest, southeastern Brazil. We also investigated reproductive effort and size-fecundity relationships in females. Reproductive traits were compared to other species in the genus Physalaemus, especially those included in the P. signifer group. Physalaemus crombiei is a prolonged breeder, reproducing throughout the year with a peak of activity during the most rainy months (October-March). Males called from the humid forest foor and eggs embedded in foam nests were deposited in the water as well as on the humid foor amidst the leaf litter, or inside fallen leaves or tree holes containing rainwater on the forest foor. As expected, P. crombiei exhibited three alternative reproductive modes, as described for other species of the P. signifer group. The number of eggs produced per female varied from 91 to 250. Female body size is positively correlated both with ovary mass and clutch size (number of eggs per clutch). Variation in the number and size of eggs observed in Physalaemus species may be explained not only by female size, but also by the terrestrial reproductive mode exhibited by the species in the P. signifer group.
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Effects due to resonances in the orbital motion of artificial satellites disturbed by the terrestrial tide are analyzed. The nodal co-rotation resonance, apsidal co-rotation resonance and the Lidov-Kozai's mechanism are studied. The effects of the resonances are analyzed through the variations of the metric orbital elements. Libration and circulation motions for high orbits with high eccentricities are verified for the Lidov-Kozai's mechanism.
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One of the most intriguing questions in ecology is how to identify which and how many species will be able to inhabit human-modified landscapes. Large-bodied mammals structure plant communities by trampling, herbivory, seed dispersal and predation, and their local extinction may have pervasive consequences in plant communities due to the breakdown of key interactions. Although much attention has been given to understanding the effects of defaunation on plant communities, information on the potential impacts on plant functional groups (seed dispersal, seed size and seedling leaves defense) inhabiting continuous forests after defaunation is scarce. We conducted mammal surveys (line transects and camera trapping) to determine the defaunation status of a continuous Atlantic forest in Brazil. Then, we evaluated the effects of defaunation on seedling diversity, richness and abundance of functional groups using 15 plot-pairs (each pair with one open and one exclusion plot) monitored over 36. months. We found that the studied area is partially defaunated because it exhibits high abundance of primates, while terrestrial mammals, such as large rodents and ungulates, are rare. We found no significant changes in either seedling richness and diversity or in the seedling composition of plant functional groups in response to mammal exclosure. Seedling mortality and recruitment were similar between plot types. Our findings suggest that at semi-defaunated areas, where arboreal species are still present, terrestrial mammals have low impacts on the plant community reassembly. © 2013 Elsevier Ltd.
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An indirect method for the georeferencing of 3D point clouds obtained with terrestrial laser scanning (TLS) data using control lines is presented. This technique could be used for rapid data acquisition where resources do not permit the use of expensive navigation sensors or the placement of pre-signalised targets. The most important characteristic is the development of a mathematical model based on the principle that the direction vector of the TLS straight line is coplanar with the plane defined by the origin of the TLS system, one endpoint of a control line and the direction vector of the control line in the ground reference coordinate system. The transformation parameters are estimated by minimising the distance between the control lines and their corresponding TLS straight lines. The proposed method was tested using both simulated and real data, and the advantages of this new approach are compared with conventional surveying methods. © 2013 This article is a U.S. Government work and is in the public domain in the USA.
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The physiological control to support the absence of O2 for long periods of diving, and oxidative damage impact caused by the whole process of hypoxia/reperfusion in freshwater turtles is well known. However, effects of contaminants may act as co-varying stressors and cause biological damage, disrupting the hypoxia/reperfusion oxidative damage control. In order to investigate the action of environmental stressors present in domestic or industrial wastewater effluent, we performed a biochemical analysis of biotransformation enzymes, oxidative stress, as well as neuromuscular, physiological and morphological parameters in Phrynops geoffroanus, an hypoxic-tolerant freshwater turtle endemic of South America, using animals sampled in urban area, contaminated by sewage and industrial effluents and animals sampled in control area. Here we demonstrate the physiological and biochemical impact caused by pollution, and the effect that these changes cause in antioxidant activity. Animals from the urban area exhibited higher EROD (ethoxyresorufin-O-deethylase, CYP1A1), GST (glutathione S-transferase), G6PDH (glucose-6-phosphate deshydrogenase), AChE (acetilcholinesterase) activities and also TEAC (trolox-equivalent antioxidant capacity) and TBARS (thiobarbituric acid reactive substances) values. We examined whether two morphometric indices (K - condition factor and HIS - hepatosomatic index) which help in assessing the general condition and possible liver disease, respectively, were modified. The K of the urban animals was significantly decreased compared to the control animals, but the HIS value was increased in animals from the urban area, supporting the idea of an impact in physiology and life quality in the urban freshwater turtles. We propose that this freshwater turtle specie have the ability to enhance its antioxidants defenses in order to protect from tissue damage caused by hypoxia and reperfusion, but also that caused by environmental contamination and that the oxidative damage control in hypoxic conditions has resulted in an adaptive condition in hypoxic-tolerant freshwater turtle species, in order to better tolerate the release of contaminated effluents resulting from human activity. © 2013 Elsevier Inc.