The Ephemeroptera family Baetidae is one of the most specious families in the Neotropical region and a great effort to improve the taxonomy of this group has been made over the last 10 years in South America. Such studies now enable the development of biomonitoring tools at species-level in the region. A total of 2,199 baetids were collected from seven sampling sites, collected three times (autumn, winter and summer), representing an environmental gradient, draining an area of Atlantic Forest remnants. We describe the mesohabitat of nine Baetidae species and evaluate their responses to environmental degradation and water chemistry by means of biological measures (richness and abundance) and multivariate analysis (Canonical Correspondence Analysis), in order to assess their potential capacity as indicators of these impacts. Most species were found predominantly associated with stony substrates, but some were associated with pool litter, and one species was found predominantly in riffle litter substrate. Species distribution was influenced by the environmental gradient. Based on the CCA ordination, we were able to identify which species were found in pristine versus the most impaired areas, therefore enabling us to establish the sensitivity of each species.

Abstract(The species of mayflies (Ephemeroptera: Insecta) recorded from Brazil). A checklist of the Brazilian Ephemeroptera fauna with all species, genera and families recorded from the country, including the states for which every species is reported, and the pertinent reference is presented. Comments on the status of knowledge of the Brazilian mayfly fauna are also provided. Up to date, 10 families, 63 genera, and 166 species are recorded. Baetidae and Leptophlebiidae have more than 50% of all records, while the North and Southeastern regions are significantly better studied than the other areas of the country.Key words: Brazil, mayflies, records, status of knowledge, South-America. Resumo(As espécies de Ephemeroptera (Insecta) registradas para o Brasil). Uma lista da fauna de Ephemeroptera do Brasil, com todas as espécies, gêneros e famílias registrados para o país é apresentada, incluindo os estados para os quais as espécies estão reportadas assim como a bibliografia pertinente. Comentários acerca do estado atual do conhecimento da fauna brasileira também são tecidos. Até o presente momento 10 famílias, 63 gêneros e 166 espécies estão registrados. As famílias Baetidae e Leptophlebiidae compreendem mais de 50% de todos os registros, enquanto as regiões Norte e Sudeste são significativamente melhor estudadas que as demais. Palavras

Protecting riparian vegetation around streams is vital in reducing the detrimental effects of environmental change on freshwater ecosystems and in maintaining aquatic biodiversity. Thus, identifying ecological thresholds is useful for defining regulatory limits and for guiding the management of riparian zones towards the conservation of freshwater biota. Using nationwide data on fish and invertebrates occurring in small Brazilian streams, we estimated thresholds of native vegetation loss in which there are abrupt changes in the occurrence and abundance of freshwater bioindicators and tested whether there are congruent responses among different biomes, biological groups and riparian buffer sizes. Mean thresholds of native vegetation cover loss varied widely among biomes, buffer sizes and biological groups: ranging from 0.5% to 77.4% for fish, from 2.9% to 37.0% for aquatic invertebrates and from 3.8% to 43.2% for a subset of aquatic invertebrates. Confidence intervals for thresholds were wide, but the minimum values of these intervals were lower for the smaller riparian buffers (50 and 100 m) than larger ones (200 and 500 m), indicating that land use should be kept away from the streams. Also, thresholds occurred at a lower percentage of riparian vegetation loss in the smaller buffers, and were critically lower for invertebrates: reducing only 6.5% of native vegetation cover within a 50‐m riparian buffer is enough to cross thresholds for invertebrates. Synthesis and applications. The high variability in biodiversity responses to loss of native riparian vegetation suggests caution in the use of a single riparian width for conservation actions or policy definitions nationwide. The most sensitive bioindicators can be used as early warning signals of abrupt changes in freshwater biodiversity. In practice, maintaining at least 50‐m wide riparian reserves on each side of streams would be more effective to protect freshwater biodiversity in Brazil. However, incentives and conservation strategies to protect even wider riparian reserves (~100 m) and also taking into consideration the regional context will promote a greater benefit. This information should be used to set conservation goals and to create complementary mechanisms and policies to protect wider riparian reserves than those currently required by the federal law.

Cloeodes Traver is atypical among Baetidae (Ephemeroptera) because it seems to possess a unique Pantropical distribution.

-In order to complement and integrate the knowledge regarding the fauna of Baetidae from Southeastern Brazil, thirteen species and nine genera of this family are recorded. Out of the twenty small minnow mayflies genera reported from Brazil, only five were not found for the region. A checklist of the species reported, including their distribution and pertinent bibliography, is presented. A pictorical key to nymphs is proposed for the identification of the genera in Southeastern Brazil. KEY WORDS: Aquatic insects, taxonomy, NeotropicsRESUMO -Com o intuito de complementar e integrar o conhecimento relativo à fauna de Baetidae do sudeste brasileiro, treze espécies e nove gêneros dessa família são registrados. Dos vinte gêneros da família relatados para o Brasil, apenas cinco não foram encontrados na Região Sudeste. Uma lista com todas as espécies registradas, incluindo sua distribuição e referências bibliográficas pertinentes, é apresentada. Uma chave ilustrada é proposta para a identificação dos gêneros no estágio ninfal registrados até o momento para a região. PALAVRAS-CHAVE: Inseto aquático, taxonomia, neotrópico726 Baetidae (Ephemeroptera) na Região Sudeste do Brasil: Novos Registros... Salles et al.Sul tem sido historicamente negligenciado e no Brasil não tem sido diferente. Desde a descrição da primeira espécie da família registrada para o País, Callibaetis fasciatus (Pictet), ainda no século XIX, até a primeira metade da década de 1990, o ritmo de documentação da fauna de Baetidae brasileira foi muito lento. Somente a partir de 1995; como reflexo tardio de mudanças conceituais ocorridas na família a partir de 1970 [e.g. Müller-Liebenau (1970, Morihara & McCafferty (1979)], que o conhecimento faunístico na América do Sul e no Brasil começou a avançar , LugoOrtiz & McCafferty 1996a, b, c, d, 1997, 1999a.Com relação à Região Sudeste, tais avanços deram-se mais recentemente ainda, em função de uma série de estudos enfatizando principalmente os estados de Minas Gerais e Rio de Janeiro (e.g. Lugo-Ortiz & McCafferty 1996d, 1999a LugoOrtiz et al. 2002;Salles & Lugo-Ortiz 2002a, b, 2003a Salles et al. , b, c, 2004Francischetti et al. 2003). A região, tida há pouco tempo como uma das menos conhecidas do Brasil e uma das áreas prioritárias no que diz respeito à documentação de seus integrantes de Baetidae (Lugo-Ortiz et al. 2002) (Oliveira & Froehlich 1997;Kikuchi & Uieda 1998; Baptista et al. 1998 Baptista et al. , 2001aMelo & Froehlich 2001;Goulart & Callisto 2003; Buss et al. 2004), a carência de informações referentes à documentação e distribuição dos gêneros e espécies da família pode ser justificada pela dificuldade em se identificar corretamente os seus integrantes, fato por sua vez gerado não só pela própria dificuldade do grupo como também pela ausência de chaves de identificação próprias para a região.Com base nos aspectos acima apresentados, o presente trabalho tem dois objetivos principais. O primeiro é complementar e integrar as informações alcançadas nos últimos anos, provendo uma série de reg...

ABSTRACT. Composition and distribution of Ephemeroptera (Insecta) in Cerrado-Amazônia transition area, Brazil. The objective of this study was to respond if exist a pattern on the spatial distributions of Ephemeroptera nymphs in different streams and rivers from Suiá-Miçú Basin, MT, and how the streams are classifying according to the species composition. Were sample 12 streams and rivers, in three periods of the year. Were collected 1,356 individuals, distributed in seven families, 31 genus and 42 species and/or morphospecies. The most abundant locals were semi-lentics and with few shaded suggering that most light in the system offer, allochthonous material and autochthonous material like food resources. The greater estimates richness was found in lotic places, emphasizing that the Ephemeroptera presents greater richness in these places, once water current is essential for organic matter transporting. So much in the grouping analysis (TWINSPAM) as in the ordination (DCA) was observed the separation of lotic and semi-lentic environments as for species composition. It had a gradient in the composition similarity of lotic and small streams for lotic and big stream and for last, semilentics. The results of this study show that the physic structure of aquatic environments affect species composition. In that way, retreat of riparian vegetation and streams dam up can take significant losses in the diversity. KEYWORDS.Aquatic insects, Suiá-Miçú River Basin, lotic and semi-lentic environments, nymphs. RESUMO.O objetivo deste trabalho foi responder se existe padrão na distribuição espacial das ninfas de Ephemeroptera em diferentes córregos e rios da bacia do Rio Suiá-Miçú, MT, e como os córregos estudados estão classificados de acordo com a composição de espécies. Na coleta foram amostrados 12 córregos e rios, em três períodos do ano. Foram coletados 1356 indivíduos, distribuídos em sete famílias, 31 gêneros e 42 espécies e/ou morfoespécies. Os locais mais abundantes foram ambientes semi-lênticos, com pouco sombreamento no leito, sugerindo que a maior entrada de luz disporia, além do material alóctone, material autóctone como fonte de alimento. A maior riqueza de espécie e/ou morfoespécie, estimada, foi em ambientes lóticos enfatizando que os Ephemeroptera apresentam maior riqueza nestes locais uma vez que a correnteza é essencial para transportar a matéria orgânica particulada. Tanto na análise de agrupamento (TWINSPAM) como na ordenação (DCA) observou-se a separação entre ambientes lóticos e semi-lênticos quanto a composição de espécies. Percebeu-se um gradiente na similaridade de composição dos ambientes lóticos de pequeno porte para ambientes lóticos de grande porte e, por fim, os semi-lênticos. Os resultados deste estudo demonstram que a estrutura física dos ambientes aquáticos afeta a composição de espécies. Dessa forma, a retirada das matas ciliares e o represamento dos córregos podem levar à perdas significativas na diversidade. PALAVRAS-CHAVE.Insetos aquáticos, bacia do rio Suiá-Miçú, ambiente lótico e semi-lênt...

Two new species of Callibaetis are described based on nymphs and adults of both genders. Specimens were collected in the states of Rio de Janeiro and Espírito Santo, in the Southeastern region of Brazil. With the description of C. fluminensis sp. n. and C. capixaba sp. n. we increase the number of species in the genus Callibaetis in Brazil to eleven.

-Community diversity is expected to reflect variations in local conditions but, recently, ecologists have started to realize that local diversity is also under pressure from global processes. As a result, the traditional view of community structure based on local interspecific interactions was replaced by the idea that community structure is a result of multiple processes acting in different spatial scales. This study is aimed at quantifying the relative importance of spatial, environmental and spatially structured processes on Ephemeroptera community in Cerrado streams in Brazil. Thirty-four rivers and streams in the Brazilian state Mato Grosso were sampled. Ephemeroptera species composition, based on abundance and presence data, was evaluated in relation to niche and neutral predictors by using a partial redundancy analysis (pRDA). Results obtained through the pRDA indicated that both environmental and spatial processes influenced Ephemeroptera abundance. On the other hand, only environmental processes showed effects on community patterns when using species presence data from preserved, altered and large streams and also when looking only at the preserved sites. When streams larger than 20 m were excluded from analysis, both environmental and spatially processes showed influence on Ephemeroptera composition. Adjusted R 2 values were higher for environmental than for spatial processes in all analyses. The relatively high influence of both environmental processes and stream width in the analyses highlights the sensitivity of mayflies assemblies to environmental variation, and emphasizes the importance of local processes, as predicted by niche theory, while neutral processes act to a lesser extent on the structure of the studied communities.