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.
The Miocene palaeogeography of the western Amazonian Foreland Basin (Venezuela, Colombia, Ecuador, Peru and western Brazil) and the Paraná Basin (mainly Argentina) are contentious. Several studies have hypothesized for and against a possible connection of these epicontinental depositional systems during Miocene. However, the lack of well defined palaeoenvironmental data, especially from the Bolivian lowlands, has hindered the delineation of the Miocene palaeogeography in these areas. The objective of this study is to provide new data concerning this problem.This paper presents sedimentological and ichnological data from the Quendeque Formation in the northern Subandean zone of Bolivia (lat. 15°S). This virtually unstudied formation relates the marine-influenced Paranan (northernmost reported occurrence lat. 18°S) and western Amazonian (southernmost reported occurrence lat. 13°S) depositional systems and is contemporaneous with them. The palaeogeographical significance of the new data and recently discovered tidal deposits from southern Peru (Madre de Dios) and western Brazil (Acre) is discussed. New palaeocurrent and rhythmite data from the Madre de Dios and Acre Sub-basins are presented.The studied deposits are interpreted as alluvial, deltaic and estuarine coastal plain. These data coupled with recently published data from south and central Bolivia indicate that thin Miocene tidally/marine influenced levels are present throughout the Bolivian forelands. The distal–proximal facies relations between the Late Miocene Chaco and Madre de Dios strata, and the south–southwest oriented palaeocurrent directions collected from the Madre de Dios Sub-basin suggest at least South Atlantic source for the marine influence in these areas. The episodically open hydrodynamic connection between the southwestern Amazonia and Paranan Sea may have provided a dispersal route, especially for fresh-water and euryhaline aquatic taxa. Thus, the results may explain the reported fossil faunal similarities between these areas and the modern biogeography of certain aquatic species.  相似文献   

2.
The present paper describes and illustrates the new speciesAverrhoidium dalyi and provides a key to the species ofAverrhoidium. The new species is known from lowland, terra firme forest in the Purus River basin, in Acre, Brazil, and from Manu National Park in Madre de Dios, Peru.
Resumen  En el presente artículo se describe, discute e ilustra la nueva especieAverrhoidium dalyi coleccionada en la cuenca del Río Purus en el estado de Acre, Brasil y en el Parque Nacional del Manu en el departamento Madre de Dios, Peru. También en el presente se provee una clave para las especies deAverrhoidium.
  相似文献   

3.
Species composition and relative abundance of copepods in Chilean fjords   总被引:2,自引:1,他引:1  
We studied the species composition of copepods in the fjordregion, Isla Madre de Dios, Chile during October 1979. Fifteennew records for the fjords are cited. We found the antarcticcopepod Paraeuchaeta antarctica which is consistent with earlyrecords of other antarctic zooplankters in the area. The analysisof relative abundances shows that changes in dominance occuronly among four most abundant species of copepods.  相似文献   

4.
Five new species of Scolytus Geoffroy, 1762 (Coleoptera: Curculionidae: Scolytinae) are described from Peru, namely Scolytus woodi, Scolytus carveli, Scolytus vagabundus, Scolytus lindemani, Scolytus mozolevskae .The following new synonym is established: Scolytus angustatus Browne, 1970 (= Scolytus facialis Schedl, 1973, syn. n.) New records of the Scolytus species in Loreto, Junin ,Cusco and Madre de Dios Provinces are given and the biology of the genus representatives is discussed.  相似文献   

5.
Venezuelan equine encephalitis virus (VEEV) has been responsible for hundreds of thousands of human and equine cases of severe disease in the Americas. A passive surveillance study was conducted in Peru, Bolivia and Ecuador to determine the arboviral etiology of febrile illness. Patients with suspected viral-associated, acute, undifferentiated febrile illness of <7 days duration were enrolled in the study and blood samples were obtained from each patient and assayed by virus isolation. Demographic and clinical information from each patient was also obtained at the time of voluntary enrollment. In 2005–2007, cases of Venezuelan equine encephalitis (VEE) were diagnosed for the first time in residents of Bolivia; the patients did not report traveling, suggesting endemic circulation of VEEV in Bolivia. In 2001 and 2003, VEE cases were also identified in Ecuador. Since 1993, VEEV has been continuously isolated from patients in Loreto, Peru, and more recently (2005), in Madre de Dios, Peru. We performed phylogenetic analyses with VEEV from Bolivia, Ecuador and Peru and compared their relationships to strains from other parts of South America. We found that VEEV subtype ID Panama/Peru genotype is the predominant one circulating in Peru. We also demonstrated that VEEV subtype ID strains circulating in Ecuador belong to the Colombia/Venezuela genotype and VEEV from Madre de Dios, Peru and Cochabamba, Bolivia belong to a new ID genotype. In summary, we identified a new major lineage of enzootic VEEV subtype ID, information that could aid in the understanding of the emergence and evolution of VEEV in South America.  相似文献   

6.
Kerry Barringer 《Brittonia》1986,38(2):128-132
Aristolochia fosteri is a new species with unusual branched trichomes collected in Pasco near Oxapampa.Aristolochia hutchisonii is a prostrate species found in Amazonas and Cajamarca that is related toA. weberbaueri.Aristolochia barbouri is a narrow-leaved, herbaceous liana from Madre de Dios.  相似文献   

7.
Ashe K 《PloS one》2012,7(3):e33305
The enormous increase in practically unregulated mining in Madre de Dios Peru is leading to massive release of liquid elemental mercury to the environment. Rapidly increasing global prices for gold are causing a massive upsurge in artisanal mining in the Peruvian Amazon, considered to be one of the most biodiverse places on the planet. This study identifies the current levels of mercury in the human population, through identifying levels of total mercury in human hair in mining zones of Madre de Dios Department and in the nearby city of Puerto Maldonado. A regression analysis reveals that fish consumption, gender, and location of residence were significant indicators of mercury levels; while duration of residence and age had no significant relationship to mercury levels. Increased fish consumption levels were the strongest indicators of increased total mercury levels across the entire population. The levels of total mercury in hair was significantly (α = 0.05) higher in mining zones, than Puerto Maldonado. In both areas men had significantly higher levels than women, likely due to a difference in metabolism or varying levels of direct involvement in gold mining- a male predominated industry. This is the first study to show the health threat that mercury poses to this region, however further research needs to be done to gain a more refined understanding of the predominant routes of exposure in this population.  相似文献   

8.
Eleutherodactylus olivaceus sp. n., a member of the E. unistrigatus group is described. The new species is known from montane rainforests of the Departamento Cochabamba, Bolivia, as well as from lowland rainforest of the Departamento Madre de Dios, Perú. E. olivaceus is mainly characterized by its predominantly olive green dorsal color and a papilla on the tip of the snout. Advertisement call and habitat of E. olivaceus are described. The occurrence of Eleutherodactylus mendax in Bolivia is briefly discussed.  相似文献   

9.
Phylogenetic analysis based on nuclear and mitochondrial DNA sequences was used to test the validity of morphospecies of catfishes of the family Astroblepidae inhabiting the southern‐most limit of their Andean distribution in the upper Ucayali and upper Madre de Dios river basins. Population samples of morphospecies designated a priori on the basis of morphological features were further diagnosed by the presence of unique and unreversed molecular synapomorphies, thereby confirming species validity for seven of nine cases. Although each are distinguished by unique combinations of morphological features, two morphospecies (designated F and H) cannot be diagnosed on the basis of apomorphic changes in molecular sequence that did not also occur in other astroblepid morphospecies or outgroup taxa. Further, one morphospecies (species G) was recovered as nested within the assemblage of populations sampled from morphospecies F, whose morphological diagnosis does not involve unique or apomorphic characters. In contrast, the absence of corroborating molecular apomorphies for species H, otherwise recognized by distinctive and uniquely derived morphological characters, suggests a history of rapid divergence and insufficient time for fixation of genetic differences. Species sharing syntopic distributions were not recovered as sister groups, and in some cases species distributed in adjacent river drainage basins were not more closely related to one another than to species distributed in more distant drainages. Three independent instances were observed of sister‐group relationships involving species distributed in both the Apurimac and Urubamba rivers (Ucayali drainage). These observations combine to suggest that the current distribution of astroblepid species in the southern region may have arisen via a complex history involving both divergence between and dispersal amongst drainage basins that is probably repeated numerous times throughout the Andean distribution of the group. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 162 , 90–102.  相似文献   

10.
Abstract. This paper is the fifth in a series designed to cover taxono-mically all species-groups of the lebiine genus Agra , whose cumulative ranges extend from southernmost Texas to northernmost Argentina. The mixta, virgata, feisthameli and ohausi groups constitute Section Feisthameli of the genus, and a key to these groups is provided. The mixta group consists of two species which have a composite range extending from southeastern Brazil to middle Mexico; the virgata group consists of nine species which have a composite range extending from southeastern Brazil to Guatemala; and the ohausi group consists of four species which have a composite range restricted to southeastern Brazil. The speciose feisthameli group is covered in a separate paper.
Among the three groups in the present paper, eleven new species are described from the following type localities: perkinsorum (MEXICO, Nayarit, 17.6 km southwest of Compostela), vate (MEXICO, Veracruz, Los Tuxtlas, La Playa Escondida), nola (REPUBLIC OF PANAMA, Panama, Cerro Campana), cadabra (EQUADOR, Pichincha, 47 km south of Santo Domingo de los Colorados, Rio Palenque Station), chocha (WEST INDIES, Trinidad, Arima Valley), phainops (FRENCH GUIANA, Pariacabo), imaginis (BRAZIL, Goias, Jatahy), inca (PERU, Madre de Dios, Rio Tambopata Reserve, 30 km (air) southwest of Puerto Maldonado), itatiaya (BRAZIL, Rio de Janeiro, Parque Nacional Itatiaya), calamitas (BRAZIL, Bahia, Itamaraju), anthrax (BRAZIL, Espirito Santo, Parque Socretama). A dot map illustrates the range of each taxon.
Distribution and relationships are discussed in general, but detailed cladistic and biogeographic analysis is deferred until taxonomy of the four groups of Section Feisthameli is completed. Species distribution correspond to Pleistocene refuges suggested by other authors based on other groups and classes of organisms.  相似文献   

11.
Surveys for Stenoma catenifer Walsingham, the avocado seed moth, and its associated larval parasitoids were conducted in the Departments of Junín, Huánuco, Cusco, and Madre de Dios in Perú. Fruit infestation levels in some areas ranged from 0 to 58%, and parasitism of S. catenifer larvae in Junín and Huánuco was 23%. Five species of hymenopteran parasitoid in two families, Braconidae (Apanteles sp., Hypomicrogaster sp., and Chelonus sp.) and Ichneumonidae (Pristeromerus sp. and Xiphosomella sp.), were reared from larvae, and one species of tachinid fly (Chrysodoria sp.) emerged from pupae. The dominant larval parasitoid, a gregarious Apanteles sp., accounted for 55% of parasitized hosts. Branch and twig tunneling by S. catenifer larvae in a commercial Hass avocado orchard was observed in Cusco. The field attractiveness of the sex pheromone of S. catenifer was demonstrated with 73% of monitoring traps deployed in three departments (Junín, Huánuco, and Cusco) catching male moths. Approximately 55% of avocado fruit sourced from the Province of Chanchamayo (Junin) and purchased at the Mercado Modelo de Frutas in La Victoria, in central Lima were infested with larvae of S. catenifer. Infested avocado fruit sold at this market could represent a potential incursion threat to coastal Hass avocado production regions in Perú that are reportedly free of this pest.  相似文献   

12.
The giant otter (Pteronura brasiliensis) is an endangered semi-aquatic carnivore of South America. We present findings on the demography of a population inhabiting the floodplain of Manu National Park, south-eastern Peru, arising from 14 annual dry season censuses over a 16 year period. The breeding system of territorial groups, including only a single breeding female with non-reproductive adult ‘helpers’, resulted in a low intrinsic rate of increase (0.03) and a slow recovery from decades of hunting for the pelt trade. This is explained by a combination of factors: (1) physiological traits such as late age at first reproduction and long generation time, (2) a high degree of reproductive skew, (3) small litters produced only once a year, and (4) a 50% mortality between den emergence and age of dispersal, as well as high mortality amongst dispersers (especially males). Female and male giant otters show similar traits with respect to average reproductive life-spans (female 5.4 yrs., male 5.2 yrs.) and average cub productivity (female 6.9, male 6.7 cubs per lifetime); the longest reproductive life spans were 11 and 13 years respectively. Individual reproductive success varied substantially and depended mainly on the duration of dominance tenure in the territory. When breeding females died, the reproductive position in the group was usually occupied by sisters or daughters (n = 11), with immigrant male partners. Male philopatry was not observed. The vulnerability of the Manu giant otter population to anthropogenic disturbance emphasises the importance of effective protection of core lake habitats in particular. Riverine forests are the most endangered ecosystem in the Department of Madre de Dios due to the concentration of gold mining, logging and agricultural activities in floodplains, highlighting the need for a giant otter habitat conservation corridor along the Madre de Dios River.  相似文献   

13.
Baird’s tapir (Tapirus bairdii) is the largest native mammal that inhabits the Neotropics, and it is enlisted as Endangered by the IUCN Red List. The historic distribution of this species included the area from southern Mexico to northern Colombia. However, its distribution and populations have been reduced drastically during the past 30 years. The main threats for Baird’s tapir are the direct persecution for subsistence hunting, habitat destruction, and habitat fragmentation. In this study, we used camera traps and occupancy models to identify the landscape characteristics that were associated with the occurrence of tapirs in the Sierra Madre de Chiapas, which is one of the most important populations of the species in Mexico, with the aim to identify areas with habitat suitability for the species. We used our best occupancy model to generate a resistance matrix to develop a model of habitat connectivity using Circuit Theory. According to the best occupancy model, the most suitable areas for this species were the forested areas located at the highest elevations of the mountain ranges that provided rugged terrain. We identified three critical corridors to allow for the connectivity of tapir populations in the Sierra Madre de Chiapas, and one of these corridors provides connectivity between this population and the population in the Ocote Biosphere Reserve. With this approach, we propose a conservation strategy for the species that incorporates a more realistic and detailed scheme of Baird’s tapir occurrence in the Sierra Madre de Chiapas region. Priority actions to conserve tapirs in the Sierra Madre de Chiapas over the long term include ensuring the complete protection of prime habitat for the species, improved connectivity by protecting forest cover, implementation mitigation measures in areas where paved roads interrupt connectivity of populations, and eradicating poaching of the species in the region completely.  相似文献   

14.
Deforestation and resulting landscape fragmentation are important concerns in many tropical areas. Deforestation is a complex process with many potential feedback loops, many of which are ignored in models that attempt to interpolate forest loss based on past deforestation rates. In addition, most ecological studies of the impacts of deforestation have focused on landscapes that are already fragmented. These studies ignore the fact that edge effects, such as anthropogenic fire, reach their maximum well before habitat connectivity is lost and may create positive feedbacks that result in further fragmentation. We developed a simple model to explore the potential influence of edge effects on fragmentation rates and used remotely sensed data from the MAP (Madre de Dios, Acre, and Pando) region of the Brazilian Amazon to parameterize the relationships of interest. Under reasonable real-world parameter combinations, edge effects can have a significant impact on deforestation rates, supporting the hypothesis that the true tipping point in a forest to pasture regime shift occurs earlier (i.e., ∼50% forest loss) than analysis of a loss in connectivity would suggest (i.e., ∼60% forest loss). Our results have important implications for understanding deforestation, edge-driven processes, regime shifts, and the management of complex pattern-process relationships.  相似文献   

15.
In the face of the continuing global biodiversity loss, it is important not only to assess the need for conservation, through e.g. gap analyses, but also to seek practical solutions for protecting biodiversity. Environmentally and socially sustainable tourism can be one such solution. We present a method to spatially link data on conservation needs and tourism-based economic opportunities, using bird-related tourism in Peru as an example. Our analysis highlighted areas in Peru where potential for such projects could be particularly high. Several areas within the central and northern Andean regions, as well as within the lowland Amazonian regions of Madre de Dios and Loreto emerge as promising for this type of activity. Mechanisms to implement conservation in these areas include e.g. conservation and ecotourism concessions, private conservation areas, and conservation easements. Some of these mechanisms also offer opportunities for local communities seeking to secure their traditional land ownership and use rights. (Spanish language abstract, Abstract S1).  相似文献   

16.
Undulated Antshrikes (Frederickena unduliger) inhabit dense lowland humid forest understory and, as with other species of antbirds, many aspects of their behavior and ecology are poorly known, especially their breeding biology. We provide the first detailed information about their breeding biology based on three nests monitored in the buffer zone of the Manu National Park, Madre de Dios, Peru, from August to December in 2012 and 2013. Nests (N = 3) were large cups woven to the crossing of two horizontal branches. Eggs were white with purplish hairlines and spots, and all three clutches consisted of two eggs. Both males and females incubated eggs and fed nestlings, but only females incubated eggs at night. Provisioning rates and time spent brooding nestlings did not differ between the sexes. Most aspects of the nesting behavior of Undulated Antshrikes in our study were similar to those reported for other species of antbirds, including placement and composition of nests, clutch size, and provisioning rate. However, incubating behavior and the duration of the nestling period of antbirds appear to be influenced by body mass, with larger species such as Undulated Antshrikes having greater nest attentiveness and longer nestling periods than smaller species. Additional studies of other species of antbirds are needed to better understand factors that might contribute to similarities and differences in the nesting behavior of thamnophilids.  相似文献   

17.
Adult tetraphyllidean tapeworms (Platyhelminthes: Eucestoda) from the spiral intestines of 3 species of potamotrygonid stingrays (Paratrygon aiereba, Potamotrygon castexi, and Portamotrygon motoro) in the Madre de Dios river in Peru were found to host numerous cysts embedded in their parenchymal tissues. Histological sections of the cysts revealed the presence of a scolex bearing 4 suckers and an unarmed apical organ consistent with larval stages of both Cyclophyllidea and Proteocephalidea. To further elucidate their identities, partial 28S ribosomal DNA (rDNA) sequences were characterized from 3 cysts and 4 adult Rhinebothrium spp. 'host' worms and screened against all available cestode 28S rDNA data. Initial BLAST screening and subsequent alignment ruled out the possibility that the cysts were cyclophyllidean, and the cyst and adult sequences were thus aligned together with all available lecanicephalidean, litobothriidean, proteocephalidean, and tetraphyllidean sequences. Sequences from all 3 cysts were identical, and phylogenetic analysis clearly placed them among derived members of the Proteocephalidea, although no exact match was found. Sequences from the adult host worms formed 2 identical pairs and grouped together with other tetraphyllidean species from rays. These results are compared with records of hyperparasites of South American catfish cestodes. This is the first confirmed record of a proteocephalidean cestode parasitizing a tetraphyllidean cestode.  相似文献   

18.
A new long-snouted Corydoras species is described from two tributaries of the río Manuripe and a tributary of the río Madre de Dios, rio Madeira basin, Peru. Corydoras fulleri can be distinguished from its congeners by having the following features: (a) branch of the temporal sensory canal at sphenotic, which gives rise to the supraorbital canal, with two pores; (b) upper tooth plate of branchial arch with three series of teeth; (c) area at the corner of the mouth, ventral to the maxillary barbel, with a small fleshy flap; (d) two moderate-sized dark-brown or black blotches on caudal-fin base, one on its lateral portion and another one on its dorsal portion, blotches variably diffuse and/or fused with each other; (e) absence of a dark-brown or black stripe transversally crossing the orbit; (f) a longitudinal dark-brown or black stripe on the postdorsal region of flank midline, variably fused with the lateral peduncular blotch, some specimens with slender, longitudinally elongated, dark-brown or black blotch on flank midline, forming a dash-like marking, stripe or dash-like blotch diffuse in some specimens; and (g) region around dorsal-fin origin generally lacking dark brown or black blotch, or displaying diffuse blotch.  相似文献   

19.
In most subfamilies of ants (Formicidae), a pygidial gland occurs in the worker’s dorsal gaster, and where tested, products of this gland function in alarm/defense and/or recruitment communication. These products are well characterized for members of the subfamily Dolichoderinae but remain unidentified for Myrmicinae. Both major and minor workers of one myrmicine, Pheidole biconstricta Mayr, are known to have greatly hypertrophied pygidial glands with alarm/repellent products. GC/MS analysis of methanol extracts of worker gasters revealed actinidine and six diastereomers of iridodials as major components, as well as lesser amounts of two lactones, iridomyrmecin and dihydronepetalactone. The iridoids also occur in the pygidial glands of some dolichoderines. Results are related to functional and phylogenetic considerations. Received 20 December 2004; revised 25 February 2005; accepted 4 March 2005. Work performed at Estación Biológica Cocha Cashu, Madre de Dios, Peru, and Virginia Military Institute, Lexington, VA.  相似文献   

20.
Aim  We analysed the distributional patterns of six terrestrial vertebrate taxa from the Oaxacan Highlands (Sierra Mazateca, Nudo de Zempoaltépetl and Sierra de Juárez) through a cladistic biogeographical approach, in order to test their naturalness as a biotic unit.
Location  The Oaxacan Highlands, Mexico.
Methods  The cladistic biogeographical analysis was based on the area cladograms of the Pseudoeurycea bellii species group (Amphibia: Plethodontidae), the genus Chlorospingus (Aves: Thraupidae), the genera Microtus , Reithrodontomys and Habromys , and the Peromyscus aztecus species group (Mammalia: Rodentia). We obtained paralogy-free subtrees, from which the components were coded in a data matrix for parsimony analysis. The data matrix was analysed with N ona through W in C lada .
Results  The parsimony analysis resulted in a single general area cladogram in which areas were fragmented following the sequence Sierra Madre Occidental, Trans-Mexican Volcanic Belt, Chiapas, Sierra Madre Oriental + Sierra Mazateca, Sierra Madre del Sur, Nudo de Zempoaltépetl and Sierra de Juárez.
Main conclusions  The general area cladogram shows that the Oaxacan Highlands do not constitute a natural unit. The Sierra Mazateca is the sister area to the Sierra Madre Oriental, whereas the Nudo de Zempoaltépetl and the Sierra de Juárez are closely related to the Sierra Madre del Sur. The events that might have caused these patterns include cycles of expansion and contraction of mountain pinyon, juniper and oak woodlands during the Pleistocene.  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