Yulie Shimano

Composição e riqueza de Odonata (Insecta) em riachos com diferentes níveis de conservação em um ecótone Cerrado-Floresta Amazônica

The removal or substitution of riparian vegetation causes disturbance in physical environment, seasonal water flow and water chemical quality. These modifications can cause decrease in species richness by local extinctions. The aim of this study was to examine the effect of disturbance in the physical environmental on the richness and species composition of Odonata adults in streams with different levels of conservation in the river Suia-Missu basin, Mato Grosso, Brazil. Modifications in the aquatic systems affected the Odonata community, probably because their ecophysiological and behavioral requirements of adults and larvae. Anisoptera species, which require sunny environments because of their body size, had higher species richness in environments with low plant cover. On the other hand, Zygoptera species, which generally inhabit streams with dense vegetation, presented a decrease in richness in disturbed environments, as a result high sunlight radiation and/or variations in temperature. Hence, in both suborders, environmental perturbations do not need to be severe to change species composition, indicating that ecosystem services could be lost, even with only partial alterations in physical environment.

Effects of environmental factors on community structure of Leptophlebiidae (Insecta, Ephemeroptera) in Cerrado streams, Brazil

O efeito de fatores ambientais sobre a abundância, riqueza de especies e grupos funcionais alimentares de Leptophlebiidae foi analisado em 16 locais pertencentes a quatro corregos de Cerrado, a partir de coletas de substrato em tres periodos de 2005. Foram amostradas 5.492 larvas distribuidas em 14 especies, classificadas em tres grupos funcionais alimentares: raspadores, coletores-filtradores e fragmentadores. A abundância e riqueza de especies nao foram afetadas por nenhum dos fatores ambientais investigados, mas a integridade dos habitats exerceu efeito positivo sobre a abundância dos fragmentadores, consequencia da intrinseca interacao desses organismos com a mata ciliar. Dessa forma, acreditamos que este trabalho agrega informacoes bioecologicas sobre as especies e grupos funcionais de insetos aquaticos e podera contribuir no monitoramento e conservacao de riachos do Cerrado.

Ephemeroptera (Insecta) ocorrentes no leste do Estado do Mato Grosso, Brasil

Aiming to present a survey of Ephemeroptera fauna of Ephemeroptera from Mato Grosso State we investigated mayfly nymphs mainly from two hydrographic basins located in the eastern area of the state. Sixty-seven species/morphospecies in 41 genera and eight families were encountered. Four species (Cloeodes redactus Waltz & McCafferty, 1987 and Waltzoyphius roberti Thomas & Peru, 2002 [Baetidae], Tricorytopsis chiriguano Molineri, 2001 [Leptohyphidae] and Microphlebia surinamensis Savage & Peters, 1983 [Leptophlebiidae]) are recorded for the first time from Brazil. The families Euthyplociidae, Polymitarcyidae and Coryphoridae are recorded for the first time from Mato Grosso, as well as 19 genera and 18 species. Twenty-five species could not be identified due to the lack of knowledge regarding the nymphal stage of their respective genera. As demonstrated in others surveys of mayflies in Brazil, the order is much more diverse than currently recognized, especially if we consider that several physiognomies and hydrographic basins of the state remain undocumented.

Study of the mayfly order Ephemeroptera (Insecta) in Brazil: a scienciometric review

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.

Ecological studies of mayflies (Insecta, Ephemeroptera): Can sampling effort be reduced without losing essential taxonomic and ecological information?

The present study evaluated the potential for the reduction of sampling effort in studies of ephemeropteran nymphs in Brazilian Amazon streams, Pará State, Brazil, without the loss of ecological information (species composition, abundance, and richness), and the congruence of different levels of taxonomic resolution (morphospecies, genus, family and functional group). Test groups of 15, 10 and five subsamples were selected from the 20 subsamples collected per stream (40 streams sampled), and were compared in terms of their species richness and abundance (ANOVA), and composition (Procrustes). Taxonomic resolution was also analyzed in Procrustes. Species abundance (F(3, 156) = 25.426; p < 0.001) and richness (F(3, 156) = 13.866, p < 0.001) varied significantly among sample groups, while the results of the 15-S group were statistically similar, in both cases, to those of the 20-S group. A similar pattern was found for species composition. The genus-level taxonomic resolution produced results 99% similar to those found for the species-level data. The results indicate that the reduction in sampling effort from 20 to 15 subsamples per site and a genus-level taxonomic resolution would not affect the reliability of analyses significantly. A reduction of five samples per site would result in a decrease of effort in the field and the amount of material to be processed, reducing laboratory time. In addition to a reduction in the time and resources needed to identify specimens, the adoption of a genus-level taxonomic resolution could help minimize errors of underor over-estimation in the processing of the results.

More on the spider genus Xeropigo O.P.-Cambridge (Araneae, Corinnidae, Corinninae): seven new species and new records from Brazil.

Seven new species of the spider genus Xeropigo O. P.-Cambridge are described from Brazil, increasing the genus member list up to 16 species. X. piripiri n. sp., X. aitatu n. sp., and X. cajuina n. sp. are described from the state of Piauí. X. crispim n. sp. is described from the states of Ceará, Piauí, and Maranhão. X. oxente n. sp. is described from the state of Rio Grande do Norte. X. canga n. sp. is described from the state of Minas Gerais. X. ufo n. sp. is described from the state of Mato Grosso. The geographical distribution of X. tridentiger, X. camilae, X. pachitea, and X. perene is updated. A key to all species of Xeropigo is presented and possible relationships among all species of the genus are discussed.