Navegando por Assunto "Ephemeroptera"

Agora exibindo 1 - 5 de 5

Acesso aberto (Open Access)
An estimate of the potential number of mayfly species (Ephemeroptera, Insecta) still to be described in Brazil
(Universidade Federal do Pará, 2015-07) MATOS, Mylena Neves Cardoso; FEITOZA, Yulie Shimano; NABOUT, João Carlos; JUEN, Leandro
This study reviewed the data on the Brazilian Ephemeroptera, based on the studies published before July, 2013, estimated the number of species still to be described, and identified which regions of the country have been the subject of least research. More than half the species are known from the description of only one developmental stage, with imagoes being described more frequently than nymphs. The Brazilian Northeast is the region with the weakest database. Body size affected description rates, with a strong tendency for the larger species to be described first. The estimated number of unknown Brazilian species was accentuated by the fact that so few species have been described so far. The steep slope of the asymptote and the considerable confidence interval of the estimate reinforce the conclusion that a large number of species are still to be described. This emphasizes the need for investments in the training of specialists in systematics and ecology for all regions of Brazil to correct these deficiencies, given the role of published papers as a primary source of information, and the fundamental importance of taxonomic knowledge for the development of effective measures for the conservation of ephemeropteran and the aquatic ecosystems they depend on.
Acesso aberto (Open Access)
Baetidae (Insecta, Ephemeroptera) em córregos do cerrado matogrossense sob diferentes níveis de preservação ambiental
(2011-09) SOUZA, Hilton Marcelo de Lima; CABETTE, Helena Soares Ramos; JUEN, Leandro
The effect of different stream environmental preservation levels, in 1st to 4th orders, over the richness, abundance, similarity in the composition and the potential of Baetidae (Ephemeroptera) species as bioindicators were investigated in a Cerrado region located in the state of Mato Grosso, Brazil. A total of twenty species/morphospecies were catalogued from the 1752 samples of nymphs, resulting in a new record for two species in Brazil. Values of Habitat Integrity Index (HII) were categorized among damaged, modified, and preserved environments. Species richness was different between sites, being greater in disturbed habitats. Total abundance was higher among preserved and altered environments, and differed significantly from the degraded areas. The NMDS analysis indicates that, in preserved and modified sites, the similarity in the composition of species differs from degraded areas. Four species showed a positive relationship with increasing values of HII. Baetidae showed environmental indicator species with different levels of preservation, with Zelusia principalis Lugo-Ortiz & McCafferty, 1998 and Baetodes sp. being indicators of preserved environments and Aturbina nigra Salles, Boldrini & Shimano, 2011, Callibaetis sp. 2, Camelobaetidius aff. janae, Paracloeodes binodulus Lugo-Ortiz & McCafferty, 1996 and Waltzoyphius roberti Thomas & Peru, 2002 as indicators of modified environments. The knowledge on the ecology of species advances in terms of providing subsidies for the biomonitoring of basins and the use of indicator species.
Acesso aberto (Open Access)
Ephemeroptera (Insecta) no Brasil: estado da arte, amostragem, influências e distribuição
(Universidade Federal do Pará, 2015) FEITOZA, Yulie Shimano; JUEN, Leandro; http://lattes.cnpq.br/1369357248133029
In this thesis we aimed to contribute to the ecological knowledge about the Ephemeroptera order in Brazil in order to decrease Wallacean, Prestonian and Hutchinsonian shortfalls related to these organisms. For this purpose, we worked with bibliographic data and field sampling, which resulted in six chapters. We summarized bibliographic information about Brazilian Ephemeroptera studies in the first chapter and for the others, we used data from collections performed in Brazilian Amazonia, also for the last chapter, we have used both dataset from collected and bibliographic source. In the first chapter, we performed a scienciometric analysis about Ephemeroptera studies in Brazil, then we have found the main gaps: absence of studies in some Brazilian states and records of families, need of studies about phylogeny, need of improvement of taxonomic resolution in ecological studies, and deficit of knowledge about environmental variables affecting Ephemeroptera distribution. In the second chapter, we proposed new sampler (circular handnet) and sampling design (150-meters along streams) to be used in ecological studies. We tested in the third chapter the effectiveness of our own methodology, where applied to verify whether 15 subsamples are enough to represent mayflies fauna (instead 20 subsamples), also discontinuos sampling are better than continuous, and if the taxonomic resolution between species and genera are highly concordants. In the fouth chapter, the community was analysed in a regional scale, where we verified differences in environment structure of streams and species composition according to interfluves and scales (local or regional). In the fifth chapter, we tested if River Hypothesis is valid for mayflies communities in Brazilian Amazon, where we found the largest rivers acting as geographic barriers structuring mayflies distribution, as well as the connection of drainage basins also affected Ephemeroptera distribution. Finally, in the last chapter we made a study of case through a new approach of Threshold Indicator Taxa Analysis (TITAN). In this chapter, we found Miroculis as a genus associated to forested areas while Ulmeritoides was associatedrelated to oil palm plantation areas;With this thesis, we increased records and knowledge of Amazonian mayflies, by reducing gaps in relation to distribution (Wallacean deficit), abundance (Prestonian defict) and environmental answers from these organisms (Hutchinsonian deficit).
Acesso aberto (Open Access)
Padrão de distribuição de larvas de EPT (Ephemeroptera, Plecoptera, Trichoptera) em riachos na Amazônia Oriental
(Universidade Federal do Pará, 2025-03) RAMOS, Thaiz Maria; JUEN, Leandro; http://lattes.cnpq.br/1369357248133029; HTTPS://ORCID.ORG/0000-0002-6188-4386; KOROIVA, Ricardo; http://lattes.cnpq.br/3262687790057613; http://orcid.org/0000-0002-6658-0824
Dispersal is the movement of organisms between habitats in the landscape. It is essential for the establishment of species in new locations and for the maintenance of genetic diversity in the region. Its efficiency depends on the dispersal capacity of individual species, environmental variables and the distance between habitats. The mechanisms of community structuring and anthropogenic impacts on aquatic invertebrates have been assessed using approaches based on species' functional traits, but the use of this method to determine species' dispersal potential is still understudied. Therefore, the dispersal potential of most species is determined indirectly based on functional traits and mainly using expert knowledge. Based on this scenario, the aim of this dissertation was to evaluate the dispersal pattern of EPT larvae (Ephemeroptera, Plecoptera and Trichoptera) and attempt to classify the dispersal potential of genera based on functional dispersal traits and relate these traits to environmental variables. The dissertation is divided into two chapters. In Chapter 1, we examine how functional dispersal traits of EPT larvae are related to environmental conditions of rivers in the eastern Amazon. Most of the traits and their categories were negatively or positively related to some of the nine physicochemical variables selected in the study. Thus, we confirm the fact that environmental conditions influence the composition of functional dispersal traits. In Chapter 2, we classify the dispersal potential of the genera of EPT larvae based on the functional dispersal traits and after consultation with experts of each order. The Ephemeroptera was the order with the most genera with high dispersal potential, while the Plecoptera genera had medium and low values for dispersal. The Trichoptera genera had very different values for dispersal potential. We also investigated whether the dispersal ability of EPT larval genera was reflected in their abundance and prevalence in the rivers of eastern Amazonia, which was not confirmed. In our study, we found that functional traits, whether related to dispersal or not, are excellent tools to be used as proxies.
Acesso aberto (Open Access)
Study of the mayfly order Ephemeroptera (Insecta) in Brazil: a scienciometric review
(Universidade Federal do Pará, 2013-12) SHIMANO, Yulie; SALLES, Frederico Falcão; JUEN, Leandro
Study of the mayfly order Ephemeroptera (Insecta) in Brazil: a scienciometric review. Despite an increase in the number of studies in recent years of the aquatic insect order Ephemeroptera (the mayflies) much still remains to be learnt. In order to identify the current state of knowledge of this group in Brazil, we performed a scienciometric analysis with the purpose of identifying the strong and weak points of Brazilian research into the group. Our research used the "Institute for Scientific Information - ISI" database and was based on the abstracts, titles and keywords of manuscripts published between 1992 and 2011. We selected the papers with the combination of the words "Ephemeroptera" and "Brazil*" based on a search in February 2012. We analyzed 92 articles, and noted a lack of studies in some Brazilian states, no specific studies about some families, and an absence of phylogenetic studies. To improve ecological studies, it is necessary to fine-tune taxonomic resolution. Moreover, there is a lack of studies investigating the environmental variables which influence the distribution of mayflies. Despite these gaps, if the rate of publication with mayflies proceeds at the same pace, we anticipate that many of these knowledge gaps will be closed.