RESUMO
The increase of human activities in recent years has significantly interfered and affected aquatic ecosystems. In this present study, we investigate the effects of urbanization in the community structure of aquatic macroinvertebrates from Atlantic Forest streams. The sampling was conducted in the mountainous region of the State of Rio de Janeiro, Brazil in 10 urban and 10 preserved streams during the dry season (August-September) of 2012. The streams were characterized for its environmental integrity conditions and physico-chemical properties of water. The macroinvertebrates were sampled on rocky substrates with a kicknet. A total of 5370 individuals were collected from all streams and were distributed among Ephemeroptera, Odonata, Plecoptera, Hemiptera, Megaloptera, Coleoptera, Trichoptera, Lepidoptera, and Diptera. In urban sites, all those orders were found, except Megaloptera, while only Mollusca was not found in preserved streams. We performed a non-metric multidimensional scaling (NMDS) analysis that separated two groups distributed among sites in urban communities and another group outside this area. The dominance was significantly higher at urban sites, while the α diversity and equitability were greater in preserved sites. A canonical correspondence analysis (CCA) was also performed, indicating that most taxa associated with high values of the Habitat Integrity Index (HII) and a few genus of the order Diptera with the high values of ammonia, total nitrogen, associated to streams in urban sites. Urban and preserved streams differ by physical-chemical variables and aquatic macroinvertebrates. In urban streams, there is most dominance, while α diversity and equitability are higher in preserved streams.
Assuntos
Biodiversidade , Monitoramento Ambiental , Florestas , Invertebrados/classificação , Animais , Brasil , Ecossistema , Insetos , Invertebrados/crescimento & desenvolvimento , Rios/química , Estações do Ano , Urbanização/tendênciasRESUMO
Conognatha (Pithiscus) coffeatus sp. nov. and Conognatha (Pithiscus) puris sp. nov., both from the Atlantic Rainforest (type locality: Itatiaia, Rio de Janeiro State, Brazil), are described and illustrated. They differ from each other mainly by the elytral colour pattern, presence of a short longitudinal groove between the vertex and the frons in C. (P.) puris sp. nov., and differences in frons shape, antennae sensory fields, pronotum and aedeagus. The distribution of C. (P.) gounellei is extended to the State of Minas Gerais, Brazil. A modified key to include the new species, as well as illustrations, are presented.
Assuntos
Besouros/classificação , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , Brasil , Besouros/anatomia & histologia , Besouros/crescimento & desenvolvimento , Ecossistema , Masculino , Tamanho do Órgão , Floresta ÚmidaRESUMO
Agrilozodes bellamyi sp. nov. from the Caatinga Biome (type locality: Juazeirinho, Paraíba, Brazil) is described and illustrated. It differs from the other five known species mainly by the moderate longitudinal elevation between the eyes, posterolateral angles of pronotum acute and oblique, mesoepisternum excavated, elytral color pattern and elevation of interestriae 2 and 4. The distribution of A. pygmaeus is extended to Rio de Janeiro, Brazil. Photographs of six species as well as a key to the six species of the genus are provided.