111 resultados para Group Approaches
Resumo:
The genus Sporophila (Cabanis, 1844) unites about 30 species of small seedeaters that predominantly inhabit open or semi-open areas in the Neotropical region. The taxonomy of this group is based on morphological studies from collected male specimens. The dynamic spatial and temporal variation in the male plumage and lack of knowledge of their vocalizations make it difficult to properly diagnose some species even today, so these two aspects account for the existing taxonomic dilemmas involving Sporophila. During a four-year field study, we investigated the natural history of a breeding population of Sporophila melanogaster (Pelzeln, 1870). This is an endemic species in Brazil, which reproduces in the high-altitude grasslands of the Atlantic Forest biome. We found four male specimens with clearly diagnosable plumage, distinct from the typical form of the species. Here we describe this previously unreported plumage form. Based on the evaluation of habitat use, vocalization, and reproductive behavior, we tested two hypotheses regarding its taxonomic status. We concluded that this is another case of an intra-specific color morph within the seedeaters of the "capuchinos" group.
Resumo:
Human interventions in natural environments are the main cause of biodiversity loss worldwide. The situation is not different in southern Brazil, home of five primate species. Although some earlier studies exist, studies on the primates of this region began to be consistently carried out in the 1980s and have continued since then. In addition to important initiatives to study and protect the highly endangered Leontopithecus caissara Lorrini & Persson, 1990 and Brachyteles arachnoides E. Geoffroy, 1806, other species, including locally threatened ones, have been the focus of research, management, and protection initiatives. Since 1993, the urban monkeys program (PMU, Programa Macacos Urbanos) has surveyed the distribution and assessed threats to populations of Alouatta guariba clamitans (Cabrera, 1940) in Porto Alegre and vicinity. PMU has developed conservation strategies on four fronts: (1) scientific research on biology and ecology, providing basic knowledge to support all other activities of the group; (2) conservation education, which emphasizes educational presentations and long-term projects in schools near howler populations, based on the flagship species approach; (3) management, analyzing conflicts involving howlers and human communities, focusing on mitigating these problems and on appropriate relocation of injured or at-risk individuals; and finally, (4) Public Policies aimed at reducing and/or preventing the impact of urban expansion, contributing to create protected areas and to strengthen environmental laws. These different approaches have contributed to protect howler monkey populations over the short term, indicating that working collectively and acting on diversified and interrelated fronts are essential to achieve conservation goals. The synergistic results of these approaches and their relationship to the prospects for primatology in southern Brazil are presented in this review.
Resumo:
Crabs of the genus Uca Leach, 1814 are characterized by having strong sexual dimorphism and a global distribution. Currently, 97 species have been described and analyzed under several aspects, including population ecology, physiology and ethology. However, there is no general summary of the information from the various literatures. The aim of this study is to perform a scientometric analysis of fiddler crab studies. For this we searched papers available in the Thomson ISI database that contained the words "Uca" OR "fiddler* crab*" between the years 1991 and 2007. For each paper, we researched and recorded the following characteristics: publication year; journal of publication; the first author's nationality; the country where the study was conducted; study type; species studied; and the work area. Our results indicated that there was no increase in the number of articles through the years considered. The Journal of Experimental Marine Biology and Ecology published most of the articles on Uca, indicating the importance of this group as a model for testing ecological hypotheses using experimental approaches. Our results also showed that United States had the highest number of authors and published studies on Uca, following the overall trend in dominance on scientific research. Furthermore, using models with three variables (per capita income, number of species of Uca and extent of coastal countries) we observed that, according to the Akaike Information Criterion, the per capita income was the most important correlate for the number of articles per country (both the author's country and country of study). Additionally, our results show that the species U. pugilator (distributed on the East Coast of the North American continent) was the species most singularly referenced in the papers considered. Moreover, our results indicate that most studies on Uca use a descriptive and local scale. The majority of papers in our literature search reflect studies in population biology, followed by behavioral and physiological characteristics.
Resumo:
The Drosophila peruensis species group was recently proposed and includes four taxa: D. atalaia Vilela & Sene, 1982, D. boraceia Vilela & Val, 2004, D. pauliceia Ratcov & Vilela, 2007, and D. peruensis Wheeler, 1959. All these species have most of setae or setulae of mesonotum arinsing from dark spots, wings with crossveins darker (except in D. atalaia) and hypandrium squared-shaped mostly fused to gonopods. Here, we describe two new species, Drosophila itacorubi sp. nov. and Drosophila paraitacorubi sp. nov., belonging to this species group. The male genitalia of these species are figured. An identification key to the D. peruensis species group is provided.
Resumo:
The new genus Neodrassex is proposed to include two new species of Gnaphosidae from Brazil. Neodrassex aureus sp. nov. is described from Amazonas, Paraná and Rio Grande do Sul states, and N. iguatemi sp. nov. is described from Paraná state. Neodrassex gen. nov. is characterized by small size, pale coloration, large anterior median eyes surrounded by black pigmentation, absence of a dorsal abdominal scutum in males and by the cheliceral dentition with 2-3 teeth on the promargin and 2-4 on the retromargin. The new genus is tentatively placed at the Leptodrassex group.
Resumo:
The adult, pupal and larval morphology of S. argentiscutum sp. nov., a member of the S. amazonicum-group, is compared with S. amazonicum Goeldi and its distribution, biology and medical importance are discussed. S. argentiscutum is one the most important anthropophilic species in the S. amazonicum-group as it is responsible, together with S. amazonicum, for the transmission of Mansonella ozzardi in Brazil.
Resumo:
Six species of phlebotomine sand flies in the genus Lutzomyia França from South America are included in the newly-created species group microps. References and illustrations of the species are given, including descriptions of two new forms - L. nematoducta n.sp., male and female from northern Brazil, and l. preclara n.sp. male from Colombia and Peru. The males in the species group microps are keyed.
Resumo:
The male and female of Lutzomyia carmelinoi n.sp., and the female only of L. baculus and L. williamsi, (Diptera:Psychodidae) are described and illustrated from specimens collected in Pará state, Brazil. A pictorial key is presented to these and the other members of the walkeri group.
Resumo:
Notes are presented on the three known Neotropical species of the Culicoides stigmalis group of boodsucking midges: alvarezi Ortiz, fluviatilis (Lutz), stigmalis Wirth, and on deanei n.sp., which is described from the state of Rio de Janeiro, Brazil. A diagnosis is given for the group, as well as a key for identification and comparative phtographs of the female wings.
Resumo:
Species of sandflies in the oswaldoi-group of the genus Lutzomyia occuring in Venezuela are reviewed. A new species, Lutzomyia saccai n. sp. is described. A distribution map and pictorial keys for males and females are provided with notes on biological and ecological data collected in Venezuela.
Resumo:
Throphozoites of Giardia duodenalis group obtained from fragments or scratched of hamster's mucosa were examined by transission electron microscopy. The fine structure of the trophozoites are presented and comapred with those described for other animals. Some of the trophozoites present the cytoplasm full of glycogen, rough endoplasmic reticulum-like structures and homogeneous inclusions not enclosed by membranes, recognized as lipid drops, which had not been observed in Giardia from other animals. The adhesive disk is composed of a layer of microtubules, from which fibrous ribbons extend into the cytoplasm; these ribbons are linked by layer of crossbridge filaments that shows an intermediary dense band, described for the first time in this paper. The authors regard this band as the result of the cross-bridge filaments slinding in the medium region between adjacent fibrous ribbons, and suggest a contractile activity for them. The role of the adhesive disk on the trophozoite mechanism of attachment to host mucosa is also discussed.
Resumo:
To a large extent, control of malaria vectors relies on the elimination of breeding sites and the application of chemical agents. There are increasing problems associated with the use of synthetic insecticides for vector control, including the evolution of resistance, the high cost of developing and registering new insecticides and an awareness of pollution from insecticide residues. These factors have stimulated interest in the application of molecular biology to the study of mosquito vectors of malaria; focussing primarily on two aspects. First, the improvement of existing control measures through the development of simplified DNA probe systems suitable for identification of vectors of malaria. The development of synthetic, non-radioactive DNA probes suitable for identification of species in the Anopheles gambiae complex is described with the aim of defining a simplified methodology wich is suitable for entomologist in the field. The second aspect to be considered is the development of completely novel strategies through the development of completely novel strategies through the genetic manipulation of insect vectors of malaria in order to alter their ability to transmit the disease. The major requirements for producing transgenic mosquitoes are outlined together with the progress wich has been made to date and discussed in relation to the prospects which this type of approach has for the future control of malaria.
Resumo:
The development of additional methods for detecting and identifuing Babesia and Plasmodium infections may be useful in disease monitoring, management and control efforts. To preliminarily evaluate sunthetic peptide-based serodiagnosis, a hydrophilic sequence (DDESEFDKEK)was selected from published BabR gene of B. bovis. Immunization of rabbits and cattle with the hemocyanin-conjugated peptide elicited antibody responses that specifically detected both P. falciparum and B. bovis antigens by immunofluorescence and Western blots. Using a dot-ELISA with this peptide, antisera from immunized and naturally-infected cattle, and immunized rodents, were specifically detected. Reactivity was weak and correlated with peptide immunization or infection. DNA-based detection using repetitive DNA was species-specific in dot-blot formats for B. bovis DNA, and in both dot-blot and in situ formats for P. falciparum; a streamlined enzymelinked synthetic DNA assay for P. falciparum detected 30 parasites/mm(cúbicos) from patient blood using either colorimetric (2-15 h color development) or chemiluminescent detection (0.5-6-min. exposures). Serodiagnostic and DNA hybridization methods may be complementary in the respective detection of both chronic and acute infections. However, recent improvements in the polymerase chain reaction (PCR) make feasible a more sensitive and uniform approach to the diagnosis of these and other infectious disease complexes, with appropriate primers and processing methods. An analysis of ribosomal DNA genes of Plasmodium and Toxoplasma identified Apicomplexa-conserved sequence regions. Specific and distinctive PCR profiles were obtained for primers spanning the internal transcribed spacer locus for each of several Plasmodium and Babesia species.