首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Aim We investigated how Pleistocene refugia and recent (c. 12,000 years ago) sea level incursions shaped genetic differentiation in mainland and island populations of the Scinax perpusillus treefrog group. Location Brazilian Atlantic Forest, São Paulo state, south‐eastern Brazil. Methods Using mitochondrial and microsatellite loci, we examined population structure and genetic diversity in three species from the S. perpusillus group, sampled from three land‐bridge islands and five mainland populations, in order to understand the roles of Pleistocene forest fragmentation and sea level incursions on genetic differentiation. We calculated metrics of relatedness and genetic diversity to assess whether island populations exhibit signatures of genetic drift and isolation. Two of the three island populations in this study have previously been described as new species based on a combination of distinct morphological and behavioural characters, thus we used the molecular datasets to determine whether phenotypic change is consistent with genetic differentiation. Results Our analyses recovered three distinct lineages or demes composed of northern mainland São Paulo populations, southern mainland São Paulo populations, and one divergent island population. The two remaining island populations clustered with samples from adjacent mainland populations. Estimates of allelic richness were significantly lower, and estimates of relatedness were significantly higher, in island populations relative to their mainland counterparts. Main conclusions Fine‐scale genetic structure across mainland populations indicates the possible existence of local refugia within São Paulo state, underscoring the small geographic scale at which populations diverge in this species‐rich region of the Atlantic Coastal Forest. Variation in genetic signatures across the three islands indicates that the populations experienced different demographic processes after marine incursions fragmented the distribution of the S. perpusillus group. Genetic signatures of inbreeding and drift in some island populations indicate that small population sizes, coupled with strong ecological selection, may be important evolutionary forces driving speciation on land‐bridge islands.  相似文献   

2.
In this study, the elements Br, Ca, Cl, Fe, Na, Rb, Se and Zn were determined in serum of a healthy elderly population residing in the São Paulo Metropolitan area, using instrumental neutron activation analysis. Comparison studies indicated that only Se concentration was significantly lower in the elderly group aged 75–91 years than those obtained for the group aged 60–74 years. Between genders, males presented lower Br concentrations and, the females lower Fe. Mean concentrations obtained for most elements were within the values reported in the literature.  相似文献   

3.
We studied the spatial and temporal variation in O2 and dissolved inorganic carbon (DIC) forms concentrations in ten subtropical watersheds located in the state of São Paulo, Brazil, with different degrees of impact by urbanization and land-use changes. Additionally, we used stable carbon isotopic composition of DIC to explain observed patterns. We found that land-cover changes and watershed geology are the main drivers of DIC distribution. Land-cover/use changes influence the riverine DIC in two ways: by replacing the original Cerrado 3 (C3)-type forest vegetation by C4-type vegetation composed of grasses (pasture), and by sugarcane. Most domestic sewage is dumped untreated into rivers in the state of São Paulo. Consequently, in the most densely populated watersheds, sewage is an important source of labile carbon and consequently of DIC to rivers. In terms of geology, although silicate weathering that produces kaolinite is the main type of weathering in the watersheds, the weathering of carbonate cements present in the geological formations of the western portion of the state of São Paulo are also an important source of DIC to rivers.  相似文献   

4.
Pumas (Puma concolor) are the second largest Neotropical felid, widespread throughout of the Americas. In Brazil, the species is presently affected by habitat destruction and fragmentation, driven often by the increase of road density. As a result, individuals are often victims of collisions with vehicles, some of which survive and are taken to zoos and other institutions for treatment. Some animals recover fully and would be fit for reintroduction into the wild. However, few attempts have been made to adequately conduct and monitor these reintroductions throughout South and Central America. We here present data on a soft-release experiment with a young male puma which was hit by a vehicle in state of São Paulo, Brazil. After 16 months in a felid conservation center, the animal recovered from the wounds and was transferred to a pre-release fenced area. Diel activity differed between the two enclosures, with that in the latter being closer to what has been described for individuals in the wild (i.e., mainly nocturnal and crepuscular activity). Prior to release, the animal was equipped with a radio collar. Monitoring showed a preference for commercial forests (Pinus spp. and Eucalyptus spp.) and avoidance of pastures and secondary forests. Later, there was a shift towards primary forest. Four hundred and thirty-three days after its release, the animal was killed in another vehicle collision, 55 km from the first one. Although sample size is small and the study period short, our data on activity, habitat preferences, and movements showed that the released animal presented ecological patterns close to those described in wild animals. This suggests that the soft-release protocol used in this study worked, giving the animal another chance to survive in the highly altered anthropogenic landscapes of state of São Paulo, Brazil.  相似文献   

5.
São Paulo is the most developed state in Brazil, but despite intense land use changes, some mammal species still inhabit remnant fragments of native vegetation of the state. We used fecal analyses to investigate prey diversity, trophic niche breadth, and trophic niche overlap of pumas, ocelots, and maned wolves in protected and non-protected areas in São Paulo state. During 18 months, we inspected more than 10,000 km of roads and trails and collected 233 fecal samples. Maned wolves showed generalist food habit, ocelots were predominantly carnivores, and pumas were strict carnivores. The European hare, an exotic species which had not yet been reported in the study area, was identified in the feces of a puma. Trophic niche breadth was the lowest for maned wolves (BA?=?0.339) and the highest for pumas (BA?=?0.723). Trophic niche overlap was high between maned wolves and ocelots (Ojk?=?0.765) and between pumas and ocelots (Ojk?=?0.639). Significantly different diets of maned wolves and ocelots were observed between dry and rainy seasons. Our findings indicate that these three species may adapt their diets to the disturbed landscapes. This is the second study characterizing food habits of ocelots in Cerrado areas but the first considering a large number of samples.  相似文献   

6.
Vacuolaria tropicalis sp. nov. is here described as a new species of Chloromonadophyceae, observed in material collected during the summer of 1968–1969 from an artificial pool behind the greenhouses in the São Paulo Botanical Garden in the city of São Paulo. It is distinguished from the three previously described species of the genus chiefly by cell shape and by colour and localisation of the chromatophores.  相似文献   

7.
Brazil has not yet approved legislation on assisted reproduction. For this reason, clinics, hospitals and semen banks active in the area follow Resolution 1358/92 of the Conselho Federal de Medicina, dated 30 September 1992. In respect to semen donation, the object of this article, the Resolution sets out that gamete donation shall be anonymous, that is, that the donor and recipients (and the children who might subsequently be born) shall not be informed of each other's identity. Thus, since recipients are unaware of the donor's identity, semen banks and the medical teams involved in assisted reproduction become the intermediaries in the process. The objective of this article is to show that, in practice, this represents disrespect for the ethical principles of autonomy, privacy and equality. The article also stresses that the problem is compounded by the racial question. In a country like Brazil, where racial classification is so flexible and goes side by side with racist attitudes, the intermediary role played by semen banks and medical teams is conditioned by their own criteria of racial classification, which are not always the same as those of donors and semen recipients. The data presented in this paper were taken from two semen banks located in the city of São Paulo (Brazil). At the time of my research, they were the only semen banks in the state of São Paulo and supplied semen to the capital (São Paulo city), the state of São Paulo, and to cities in other Brazilian states where semen banks were not available.  相似文献   

8.
BackgroundCancer is a leading cause of morbidity and mortality in Brazil and the burden is rising. To better inform tailored cancer actions, we compare incidence and mortality profiles according to small areas in the capital and northeast region of the State of São Paulo for the leading cancer types.MethodsNew cancer cases were obtained from cancer registries covering the department of Barretos (2003–2017) and the municipality of São Paulo (2001–2015). Cancer deaths for the same period were obtained from a Brazilian public government database. Age-standardized rates per 100,000 persons-years by cancer and sex are presented as thematic maps, by municipality for Barretos region, and by district for São Paulo.ResultsProstate and breast cancer were the leading forms of cancer incidence in Barretos, with lung cancer leading in terms of cancer mortality in both regions. The highest incidence and mortality rates were seen in municipalities from the northeast of Barretos region in both sexes, while elevated incidence rates were mainly found in São Paulo districts with high and very high socioeconomic status (SES), with mortality rates more dispersed. Breast cancer incidence rates in São Paulo were 30 % higher than Barretos, notably in high and very high SES districts, while corresponding rates of cervical cancer conveyed the opposite profile, with elevated rates in low and medium SES districts.ConclusionsThere is substantial diversity in the cancer profiles in the two regions, by cancer type and sex, with a clear relation between the cancer incidence and mortality patterns observed at the district level and corresponding SES in the capital.  相似文献   

9.
São Paulo is the most populous, developed and industrialized state of Brazil. Despite of intensive human activities, large habitat loss and fragmentation of the native vegetation cover, pumas (Puma concolor) still inhabit remnant habitat fragments in the northeastern area of the state. We investigated the occurrence of genetic structure and levels of genetic variability on pumas to aggregate basic information for conservation efforts to maintain long term viable populations of this top-predator in the region. By analyzing microsatellite loci variation, we corroborated the hypothesis of absence of genetic structure, and estimated high levels of genetic diversity (expected heterozygosity of 0.79 and mean of 10 alleles per locus). In spite of the increasing number of roadkilling and puma-human conflicts in the area, apparently pumas still maintain some level of gene flow between protected areas of the region. The observed excess of heterozygotes suggests a recent bottleneck event in this population, probably a consequence of the profound landscape transformation of the studied area during the last century; another possibility is this may be due to the observed deviation in the population sex ratio, which may be influencing the pumas’ mating system. We propose that: (1) landscape management in the study area should be focused on increasing habitat connectivity, creating protected areas and structures to allow highway crossing of pumas; (2) educational actions should be undertaken to change community perception of large carnivores, and possibly the implementation of compensatory actions to ranchers.  相似文献   

10.
A study in a remnant of cerrado vegetation in São Paulo State, Brazil, was carried out to investigate the possible role of leaf-cutting ants in the creation of nutrient-rich patches and their consequent influence on plant establishment and growth. The results showed that leaf-cutting ants had neither detectable effect on local nutrient enrichment nor on plant community structure. It is suggested that leaf-cutting ants may affect early successional stages of the vegetation, when colonies are more abundant and disperse into the habitat. Foi feito um estudo em um remanescente de vegetação de cerrado no Estado de São Paulo, com o objetivo de testar o papel das sa£vas na criação de manchas ricas em nutrientes e sua conseqüente influência no estabelecimento e crescimento das plantas. Os resultados mostraram que as saúvas não tiveram nenhum efeito detectável no enriquecimento local de nutrientes e nem na estrutura das comunidades vegetais. Sugere-se que as saúvas possam afetar os estádios iniciais da sucessão vegetal, quando as colônias são mais abundantes e dispersam-se mais no habitat.  相似文献   

11.
Knowledge of the main reproductive parameters of a species is fundamental for comprehension of the reproductive behavior of a species within its habitat. To evaluate the reproductive biology of curimbatá, Prochilodus argenteus, an important species for commercial fisheries of the São Francisco River basin, Brazil, 153 females and 174 males were captured during 1999–2000 in the São Francisco River. The females (maximum total length 71.2 cm and maximum weight 7.8 kg) were larger than the males (65.0 cm and 4.3 kg). The weight–length ratio indicated isometric growth for females (b = 3.15) and for males (b = 3.04). Prochilodus argenteus presented total spawning from October to January. Increase in rainfall was the main triggering factor for reproduction, showing a positive correlation with the gonadosomatic index (r = 0.84 females; r = 0.95 males). Size at gonadal maturation of females and males was 31.0 and 25.5 cm, respectively. This study provides information to aid in future implementation of captive breeding and management practices that intend to reduce the ongoing depletion of natural stocks.  相似文献   

12.
This study analyzed the size at sexual maturity and reproductive period of populations of Hepatus pudibundus in three bays on the northern coast of São Paulo, Brazil. Crabs were collected monthly and the bottom-water temperature was measured at each collection point. The animals were sexed, measured for carapace width (CW), and their gonadal stages were determined. A total of 8,674 specimens were collected (2,435 males and 6,239 females). Adult males showed the highest mean CW; the size at maturity for both sexes was 32.5 mm CW. Reproduction was continuous and peaked in spring and summer, because of the greater availability of plankton food for the larvae. This pattern is typical in tropical and subtropical regions, unlike the seasonal reproduction found in temperate regions. Reproductive activity of females was not significantly correlated with bottom-water temperatures. Immatures and individuals in all stages of gonadal development were found throughout the sampling period and at all depths, probably because the species completes its entire reproductive cycle in that area.  相似文献   

13.
Petrolisthes armatus (Gibbes, 1850) life history was evaluated based on growth and reproduction. Specimens were captured at Ubatuba (Brazil), identified, sexed and measured: carapace (CL, length; CW, width), larger cheliped propodus (PL, length; PW, width; and PH, height), and 2th and 5th abdominal somite (AW2 and AW5, width). Relative growth was studied using CL as independent variable and its relation with other variables (dependents), to estimate puberty size and morphological maturity. Fecundity was represented by number of eggs vs. body size CL, with a better fit using a power function. Considering the 257 specimens analyzed, males were larger than females, and the overall sex ratio was 1:1, with some differences among size classes. Maturity (puberty size) was revealed by: AW2 × CL (males: 8.6 mm CL; females: 7.6 mm CL); and AW5 × CL (7.1 and 7.6 mm CL, respectively). Reproduction was continuous, but more intense in rainy season and recruitment occurring in dry season. Fecundity of this species was 228 ± 163 eggs, with better fit by a power function (R2 = 0.72). Maturity size and growth differed when a pristine area (Ubatuba) was compared with a polluted area (São Sebastião), in the same Brazilian area (São Paulo State).  相似文献   

14.
A total of 12 free-ranging muriquis (Brachyteles arachnoides) were captured with Telazol® at Fazenda Esmeralda, Minas Gerais, Brazil, and at Fazenda Barreiro Rico, São Paulo, Brazil. All animals were measured, marked, weighed, and released. Previously reported data suggested that Brachyteles is a sexually dimorphic species with female-male body weights of 12–15 kg, respectively. We found no statistically significant difference in body weight between females (mean = 8.4 kg, range = 6.9–9.3 kg, n = 4), and males (mean =9.6 kg, range = 9.3–10.2 kg, n = 4). Our results are at variance with previously published body weights in the literature. Larger sample size may reveal a significant sexual difference, particularly in body weight. © 1993 Wiley-Liss, Inc.  相似文献   

15.
In the state of São Paulo in southeastern Brazil, a dangerous decree allows the culture of hybrids and non-native extralimital fish species in the Paraná and East Atlantic River basins. We recorded the illegal importation and sale of the non-native striped catfish Pangasianodon hypophthalmus in northeastern, central-western, southeastern, and southern areas of the country. This species is already consumed across Brazil and is cultivated for ornamental purposes. Besides escapes from fish farms and ‘fish and pays’, P. hypophthalmus can reach natural environments through aquarium dumping and ornamental ponds, motivated by its large size that reach after being sold at small size. The species has been introduced in many countries, and if established in Brazil, could put native Brazilian biodiversity and ecosystems at risk. Although importing specimens of P. hypophthalmus is prohibited by law, Decree 62.243/2016 in the state of São Paulo creates a new opportunity for invasion. In fact, once a novel fish species is moved to a new continent, it is irrational to supposed that it will stay static just in the area for which it was intended. In general, the fish disperse in the novel area on their own, by escapes from captivity or deliberate and illicit releases by persons or associations. The unwise attitude of Brazilian decision-makers and lay people in their attempt to develop aquaculture with non-native species goes against the objectives of responsible aquaculture based in native species.  相似文献   

16.
Abstract: We used remotely triggered cameras to collect data on Puma (Puma concolor) abundance and occupancy in an area of tropical forest in Brazil where the species' status is poorly known. To evaluate factors influencing puma occupancy we used data from 5 sampling campaigns in 3 consecutive years (2005 to 2007) and 2 seasons (wet and dry), at a state park and a private forest reserve. We estimated puma numbers and density for the 2007 sampling data by developing a standardized individual identification method. We based individual identification on 1) time-stable parameters (SP; physical features that do not change over time), and 2) time-variable parameters (VP; marks that could change over time such as scars and botfly marks). Following individual identification we established a capture-recapture history and analyzed it using closed population capture-mark-recapture models. Puma capture probability was influenced by camera placement (roads vs. trails), sampling year, and prey richness. Puma occupancy was positively associated with species richness and there was a correlation between relative puma and jaguar (Panthera onca) abundance. Identifications enabled us to generate 8 VP histories for each photographed flank, corresponding to 8 individuals. We estimated the sampled population at 9 pumas (SE = 1.03, 95% CI = 8–10 individuals) translating to a density of 3.40 pumas/100 km2. Information collected using camera-traps can effectively be used to assess puma population size in tropical forests. As habitat progressively disappears and South American felines become more vulnerable, our results support the critical importance of private forest reserves for conservation.  相似文献   

17.
Biological control of Diatraea saccharalis is regarded as one of the best examples of successful classical biological control in Brazil. Since the introduction of the exotic parasitoid Cotesia flavipes, the decrease of D. saccharalis infestation in sugarcane fields has been attributed to the effectiveness of this agent. Recently, the native tachinid fly parasitoids (Lydella minense and Paratheresia claripalpis) have also been implicated in the success. Here, we investigated the spatial and temporal population interactions between C. flavipes and the tachinid flies, and provide a critical analysis of the biological control practice, focusing on the undesirable effects of introductions of exotic natural enemies. To investigate these questions, a large data set comprising information from two sugarcane mills located in the state of São Paulo, Brazil (Barra and São João Mills), was analysed. Analysis of the correlation between C. flavipes and tachinid fly population densities through time revealed that such populations were inversely correlated in the São João Mill and not correlated in the Barra Mill. Logistic regressions were computed to investigate the proportion of sites occupied by the parasitoid species at both mills as a function of time. An increasing trend in the proportion of sites occupied by C. flavipes was observed, with a concomitant decrease of the sites occupied by tachinid flies. This effect was more intense in the São João Mill. Thus, there is a convincing possibility that constant releases of C. flavipes decreased the tachinid fly populations, resulting in an undesirable effect of biological control practice.  相似文献   

18.
Casearia sylvestris Sw. is a widespread neotropical tree utilized in popular medicine. Recent research ranked Casearia as one of the most promising genus in the search of drugs against cancer. Despite its wide distribution and pharmacological importance, no microsatellite markers have yet been developed for this genus. In this study, we provide 10 polymorphic microsatellite loci specifically designed for C. sylvestris, used to analyse 90 individuals distributed in two populations from São Paulo state, Brazil. On average, 12.3 alleles per locus were identified, showing the ability of the markers to detect microsatellite polymorphism in this species.  相似文献   

19.
Néo DM  Bertollo LA  Filho OM 《Genetica》2000,108(3):211-215
Specimens of Astyanax scabripinnisfrom three different altitudes (1920, 1800 and 700?m) along the Ribeirão Grande stream in the Campos do Jordão region (São Paulo State, Brazil) were investigated. The same diploid number, 2n?=?50, was detected in the three populations, with the following karyotypic constitution: 6M, 22SM, 10ST and 12A. The populations located at 1920 and 1800?m altitude presented a high incidence of B chromosomes varying in number (0–2), shape (meta- and submetacentrics), size (large and small) and sex-related frequency (they were more frequent among females). The two morphologically variant B chromosomes probably evolved from a metacentric macrochromosome, which is the most commonly observed B chromosome in several A. scabripinnispopulations.  相似文献   

20.
In order to investigate phenological patterns and seasonal and geographic variations in the preference for fragrances of Euglossini males, monthly sampling was carried out from August 2007 to July 2009 in two coastal areas of Atlantic Forest in Ubatuba, northern coast of the state of São Paulo. Fourteen aromatic baits were used, 3 of them in the first year (August 2007 to July 2008) and the other 11 in the second year (August 2008 to July 2009). A total of 1,475 individuals from 22 species were collected. The highest frequency of the individuals of the majority of the sampled species occurred in the hot/super-humid season. However, Eulaema cingulata (Fabricius) showed peaks of abundance in the cold/less-humid season on Anchieta Island. Seasonal variation in fragrance choice by males was not registered. Males of El. cingulata showed preference for β-ionone on Anchieta Island and for benzyl acetate in the Picinguaba region, characterizing the single example of geographic variation in preference for scent baits we recorded.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号