270 resultados para Endangered Species

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)


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The conservation of emblematic threatened species is in highlight nowadays. Interestingly, few invertebrate groups attract scientific attention on this issue while they constitute the vast majority of animal biodiversity. Nevertheless, many invertebrate species are nowadays at risk of extinction. This means that plenty of species are currently disappearing out of sight. During a survey in the southwestern Atlantic Ocean tubes of an endangered species of cerianthid were sampled. This study reports for the very first time the occurrence of the species Phoronis australis in southwestern Atlantic waters and the association of phoronids with the genus Ceriantheomorphe. This raises questions on mutual extinction risks for symbiotic species and also on the criteria for their inclusion on Red Lists.

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Premise of the study: Microsatellite primers were developed for Aulonemia aristulata, an endangered species of economic interest, to further describe its genetic variability and population structure. We also tested cross-amplification in 18 other bamboo species. Methods and Results: Using an enrichment genomic library, 13 microsatellite loci were isolated and characterized in A. aristulata. Seven of these loci were polymorphic. Twelve markers were cross-amplified in at least ten of the tested bamboo species. Conclusions: These markers will be useful for studies on the genetic diversity and structure of A. aristulata, which are important for future conservation, management and breeding programs of this species.

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Background: The thin-spined porcupine, also known as the bristle-spined rat, Chaetomys subspinosus (Olfers, 1818), the only member of its genus, figures among Brazilian endangered species. In addition to being threatened, it is poorly known, and even its taxonomic status at the family level has long been controversial. The genus Chaetomys was originally regarded as a porcupine in the family Erethizontidae, but some authors classified it as a spiny-rat in the family Echimyidae. Although the dispute seems to be settled in favor of the erethizontid advocates, further discussion of its affinities should be based on a phylogenetic framework. In the present study, we used nucleotide-sequence data from the complete mitochondrial cytochrome b gene and karyotypic information to address this issue. Our molecular analyses included one individual of Chaetomys subspinosus from the state of Bahia in northeastern Brazil, and other hystricognaths. Results: All topologies recovered in our molecular phylogenetic analyses strongly supported Chaetomys subspinosus as a sister clade of the erethizontids. Cytogenetically, Chaetomys subspinosus showed 2n = 52 and FN = 76. Although the sexual pair could not be identified, we assumed that the X chromosome is biarmed. The karyotype included 13 large to medium metacentric and submetacentric chromosome pairs, one small subtelocentric pair, and 12 small acrocentric pairs. The subtelocentric pair 14 had a terminal secondary constriction in the short arm, corresponding to the nucleolar organizer region (Ag-NOR), similar to the erethizontid Sphiggurus villosus, 2n = 42 and FN = 76, and different from the echimyids, in which the secondary constriction is interstitial. Conclusion: Both molecular phylogenies and karyotypical evidence indicated that Chaetomys is closely related to the Erethizontidae rather than to the Echimyidae, although in a basal position relative to the rest of the Erethizontidae. The high levels of molecular and morphological divergence suggest that Chaetomys belongs to an early radiation of the Erethizontidae that may have occurred in the Early Miocene, and should be assigned to its own subfamily, the Chaetomyinae.

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The selection of candidate plus trees of desirable phenotypes from tropical forest trees and the rapid devastation of the natural environments in which these trees are found have created the need for a more detailed knowledge of the floral and reproductive biology of tropical tree species. In this article, the organogenic processes related to unisexual flower development in tropical mahogany, Swietenia macrophylla, are described. Mahogany inflorescences at different developmental stages were evaluated using scanning electron microscopy or optical microscopy of histological sections. The unisexual flowers of S. macrophylla are usually formed in a thyrse, in which the positions of the female and male flowers are not random. Differences between male and female flowers arise late during development. Both female and male flowers can only be structurally distinguished after stage 9, where ovule primordia development is arrested in male flowers and microspore development is aborted in female flower anthers. After this stage, male and female flowers can be distinguished by the naked eye as a result of differences in the dimensions of the gynoecium. The floral characteristics of S. macrophylla (distribution of male and female flowers within the inflorescence, and the relative number of male to female flowers) have practical implications for conservation strategies of this endangered species. (c) 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 156, 529-535.

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The Hyacinth Macaw (Anodorhynchus hyacinthinus) is one of 14 endangered species in the family Psittacidae occurring in Brazil, with an estimated total population of 6,500 specimens. We used nuclear molecular markers (single locus minisatellites and microsatellites) and 472 bp of the mitochondrial DNA control region to characterize levels of genetic variability in this species and to assess the degree of gene flow among three nesting sites in Brazil (Pantanal do Abobral, Pantanal de Miranda and Piaui). The origin of five apprehended specimens was also investigated. The results suggest that, in comparison to other species of parrots, Hyacinth Macaws possess relatively lower genetic variation and that individuals from two different localities within the Pantanal (Abobral and Miranda) belong to a unique interbreeding population and are genetically distinct at nuclear level from birds from the state of Piaui. The analyses of the five apprehended birds suggest that the Pantanal is not the source of birds for illegal trade, but their precise origin could not be assigned. The low genetic variability detected in the Hyacinth Macaw does not seem to pose a threat to the survival of this species. Nevertheless, habitat destruction and nest poaching are the most important factors negatively affecting their populations in the wild. The observed genetic structure emphasizes the need of protection of Hyacinth Macaws from different regions in order to maintain the genetic diversity of this species.

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Orthophytum is a bromeliad genus restricted to Brazil with records for the states of Paraiba, Pernambuco, Alagoas, Sergipe, Bahia, Espirito Santo and Minas Gerais. The genus is usually divided in two informal groups based on the presence or absence of a peduncle. This paper presents a taxonomic revision of the 12 species in the group with sessile inflorescences and descriptions of the genus and species, nomenclatural and ecological notes, as well as illustrations are provided. The new species Orthophytum ulei is described. The conservation status for each species is evaluated using the World Conservation Union (IUCN) criteria.

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Parasites of wild primates are important for conservation biology and human health due to their high potential to infect humans. In the Amazon region, non-human primates are commonly infected by Trypanosoma cruzi and T rangeli, which are also infective to man and several mammals. This is the first survey of trypanosomiasis in a critically endangered species of tamarin, Saguinus bicolor (Callitrichidae), from the Brazilian Amazon Rainforest. Of the 96 free-ranging specimens of S. bicolor examined 45 (46.8%) yielded blood smears positive for trypanosomes. T rangeli was detected in blood smears of 38 monkeys (39.6%) whereas T. cruzi was never detected. Seven animals (7.3%) presented trypanosomes of the subgenus Megatrypanum. Hemocultures detected 84 positive tamarins (87.5%). Seventy-two of 84 (85.7%) were morphologically diagnosed as T rangeli and 3 (3.1%) as T. cruzi. Nine tamarins (9.4%) yielded mixed cultures of these two species, which after successive passages generated six cultures exclusively of T. cruzi and two of T rangeli, with only one culture remaining mixed. Of the 72 cultures positive for T rangeli, 62 remained as established cultures and were genotyped: 8 were assigned to phylogenetic lineage A (12.9%) and 54 to lineage B (87.1%). Ten established cultures of T. cruzi were genotyped as TCI lineage (100%). Transmission of both trypanosome species, their potential risk to this endangered species and the role of wild primates as reservoirs for trypanosomes infective to humans are discussed. (C) 2008 Elsevier B.V. All rights reserved.

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Ichthyofaunistic surveys in the Atlantic Rainforest have been published in relatively few works, in spite of the major biological importance of this once vast biome which is rapidly vanishing due to disordered human population growth and natural resources overexploitation. The present study aimed to access the fish fauna of a relatively well preserved basin between the cities of Santos and Cubatão (SP), an area highly modified by human activities where recent ichthyofaunistic surveys are still missing. Collections were made during three field trips in Rio Jurubatuba, a medium sized costal river, and Riacho Sabão, one of its main tributaries. A total of 2773 specimens were sampled, representing 25 species from 14 families. Six species were primary marine using the upper reaches of Rio Jurubatuba. Twelve of the 19 freshwater species are endemic of the Atlantic Rainforest and four are present in regional lists of endangered species. Only five species occurred in both Rio Jurubatuba and Riacho Sabão. The most diverse family was Characidae, followed by Poeciliidae, Rivulidae and Heptapteridae. Phalloceros caudimaculatus was the most abundant species, followed by Poecilia vivipara and Geophagus brasiliensis. The study area is considered well preserved and due to its critical location, urges for conservation policies to protect its fish diversity.

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The green turtle Chelonia mydas feeds and nests in the Brazilian coastal area and is considered an endangered species by the World Conservation Union (IUCN 2009) and threatened by the Red List of Brazilian Fauna (Ministério do Meio Ambiente 2009). Fibropapillomatosis is a disease characterized by benign skin tumors (fibropapillomas), and it is one of the main threats to the survival of this species. Studies suggest the involvement of viruses as infectious agents associated with environmental and genetic factors. Blood samples were collected from 45 turtles captured in the coastal area of the state of Sao Paulo, Brazil. From these, 27 were affected by fibropapillomas and 18 were tumor free. Biometrical data on the turtles, size, location and quantity of tumors were recorded. The area occupied by fibropapillomas per animal was calculated and four groups were determined according to severity of the disease or its absence. The objective of the study was to compare hemogram results of the sea turtles classified in these four groups. The lowest hematocrit value was observed in severely affected animals. In the hemoglobin assay, the highest value was observed in the group of tumor free turtles and the lowest, in animals severely affected. Lymphocyte counts and curved carapace length were on the verge of statistical significance.

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Background and Aims Plant growth regulators play an important role in seed germination. However, much of the current knowledge about their function during seed germination was obtained using orthodox seeds as model systems, and there is a paucity of information about the role of plant growth regulators during germination of recalcitrant seeds. In the present work, two endangered woody species with recalcitrant seeds, Araucaria angustifolia (Gymnosperm) and Ocotea odorifera (Angiosperm), native to the Atlantic Rain Forest, Brazil, were used to study the mobilization of polyamines (PAs), indole-acetic acid (IAA) and abscisic acid (ABA) during seed germination. Methods Data were sampled from embryos of O. odorifera and embryos and megagametophytes of A. angustifolia throughout the germination process. Biochemical analyses were carried out in HPLC. Key Results During seed germination, an increase in the (Spd + Spm) : Put ratio was recorded in embryos in both species. An increase in IAA and PA levels was also observed during seed germination in both embryos, while ABA levels showed a decrease in O. odorifera and an increase in A. angustifolia embryos throughout the period studied. Conclusions The (Spd + Spm) : Put ratio could be used as a marker for germination completion. The increase in IAA levels, prior to germination, could be associated with variations in PA content. The ABA mobilization observed in the embryos could represent a greater resistance to this hormone in recalcitrant seeds, in comparison to orthodox seeds, opening a new perspective for studies on the effects of this regulator in recalcitrant seeds. The gymnosperm seed, though without a connective tissue between megagametophyte and embryo, seems to be able to maintain communication between the tissues, based on the likely transport of plant growth regulators.

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The "surubim do Paraíba" (Steindachneridion parahybae) is a freshwater catfish endemic to the Paraíba do Sul River basin, Brazil. This species has been seriously threatened by environmental disturbances in the last several decades. Wild Steindachneridion parahybae males and females were collected in 2003 and taken to the hatchery of a power plant of the Companhia Energética de São Paulo (CESP). Steindachneridion parahybae broodstocks were artificially induced to reproduce in December 2003 using a combination of carp pituitary extract (CPE) and human chorionic gonadotropin (hCG). Oocytes and milt were stripped; the fertilized eggs were transferred to 60-liter conical incubators and hatched larvae distributed in nine horizontal trays. Exogenous feed was started just after yolk sac absorption. A high rate of cannibalism and photophobia were observed during the larval period, resulting in a 26% survival rate from larvae to fingerlings.

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From a genomic library enriched for GA/CA repeats, 15 highly polymorphic microsatellite markers were developed for Cariniana estrellensis, a tropical forest tree. The microsatellite loci were screened in 49 mature trees found between Pardo river and Mogi-Gua double dagger u river basins, in the state of So Paulo, Brazil. A total of 140 alleles were detected with an average of 9.33 alleles per locus. The expected heterozygosity ranged from 0.37 to 0.88. These loci showed a high probability of paternity exclusion. Additionally, 12 loci were effectively transferred to Cariniana legalis. High levels of polymorphism make the present SSR markers useful for population genetic studies.

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This study investigated the effects of stocking density on the growth and fatty acid (FA) of Brycon insignis metabolism. Fingerlings (360) were distributed into eight ponds at two stocking densities (105 and 210 g/m(3)). The analysis of growth showed that the condition factor (K) and the coefficient of variation (CV) for body mass were not affected by stocking density. However, final body mass and length, specific growth rate (SGR), and weight gain (WG) were higher in the low stocking density group, which also presented a higher feed efficiency (FE) and survival (S). By contrast, muscle protein levels were higher in the high stocking density group. The plasma and muscle lipid content were not affected by stocking density, but fish reared at lower stocking density presented higher lipid concentration in the liver, with no differences in hepatosomatic index values. Even with the differences observed in metabolic and growth parameters, plasma cortisol was not affected by stocking density. The FA profile in the muscle and liver neutral fraction were not affected by stocking density, but the FA in the polar fractions differed between the two stocking densities. In the liver, total polyunsaturated fatty acids (PUFA) and PUFA n - 3 increased in higher stocking density, mainly due to an increase in docosahexaenoic acid (DHA). In addition, PUFA n - 6 were also increased in the higher stocking density group, mainly due to an increase in arachidonic acid (AA) and docosadienoic acid (22:2n - 6). In the muscle polar fraction, the saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) decreased in the animals from the higher stocking density group, and this reduction was compensated by an increase in PUFA n - 3 and PUFA n - 6, mainly the FA with 20-22 carbons (20:4n - 6: 22:4:n - 6; 22:5n - 6, 22:5n - 3, and 22:6n - 3). A different profile was observed for the C18 PUFAs, mainly 18:2n - 6 and 18:4n - 6, which were higher in the lower density stocking group. The data suggest that when living in high stocking density, B. insignis differentially utilizes the hepatic lipids as energy source and remodels the membrane fatty acids, with higher amounts of DHA in the polar muscle fraction compensated for by a decrease in MUFA. The zootechnical and physiological indices reveal that the lower stocking density group achieve overall better performance. (C) 2010 Elsevier B.V. All rights reserved.

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Cross-amplification was tested and variability in microsatellite primers (designed for Neotropical parrots) compared, in five macaw species, viz., three endangered blue macaws (Cyanopsitta spixii [extinct in the wild], Anodorhynchus leari [endangered] and Anodorhynchus hyacinthinus [vulnerable]), and two unthreatened red macaws (Ara chloropterus and Ara macao). Among the primers tested, 84.6% successfully amplified products in C. spixii, 83.3% in A. leari, 76.4% in A. hyacinthinus, 78.6% in A. chloropterus and 71.4% in A. macao. The mean expected heterozygosity estimated for each species, and based on loci analyzed in all the five, ranged from 0.33 (A. hyacinthinus) to 0.85 (A. macao). As expected, the results revealed lower levels of genetic variability in threatened macaw species than in unthreatened. The low combined probability of genetic identity and the moderate to high potential for paternity exclusion, indicate the utility of the microsatellite loci set selected for each macaw species in kinship and population studies, thus constituting an aid in planning in-situ and ex-situ conservation.

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The genus Callistomys belongs to the rodent family Echimyidae, subfamily Echimyinae, and its only living representative is Callistomys pictus, a rare and vulnerable endemic species of the state of Bahia, Brazil. Callistomys has been previously classified as Nelomys, Loncheres, Isothrix and Echimys. In this paper we present the karyotype of Callistomys pictus, including CBG and GTG-banding patterns and silver staining of the nucleolus organizer regions (Ag-NORs). Comments on Callistomys pictus morphological traits and a compilation of Echimyinae chromosomal data are also included. Our analyses revealed that Callistomys can be recognized both by its distintinctive morphology and by its karyotype.