Estudos da fauna de Chironomidae (Diptera) nos córregos galharada, campo do meio e casquilho do parque estadual de Campos do Jordão, SP.

Chironomidae is an important group among the aquatic Diptera significantly participating in the composition of the benthic macroinvertebrate community of a vaariety of aquatic systems. It has been estimated that there exists at least 2.000-3.000 species in each biogeographical region. In Brazil, however, there are few studies on the ecology and taxonomy of this group. In Sao Paulo State 89 genera and 66 species were registered so far. Aiming to contribute to the advance in the knowledge on this family, the present work analized the Chironominae occurring at the State Park of Campos de Jordao, considering the absence of data regarding this family for that region which has peculiar characteristics for Sao Paulo State, such as: high altitude and subtropical high a altitude temperate climate. Samplings for the immature phase were performed by using a Surber type sampler and a D net. The samples were taken at the rivers Galharada and its affluent, Campo do Meio and Casquilho, all them of low order, with stony beds, protected by riparian vegetation; The water is transparent, cold, well oxygenated, acid, with low electrical conductivity and turbidity. Adults were captured close to the sampling points of the larvae using light trap. The results revealed differences in the structure of the communities among the streams. From cluster analysis it was possible to see the clustering of Galharada sampling points located in a central region of the park and mainly represented by the taxa aff.Omisus sp1 and Corynoneura. On the other hand the sampling points Campo do Meio and Casquilho, suffering anthropogenic impacts presented a dominance of aff. Pseudochironomus sp1 species. The diversity of adult specimens was higher than that of larvae, and new records of species for Sao Paulo State were found (Neelamia) and Brazil (Paramerina), as well as new species (Antillocladius sp1 and Goeldichironomus sp). The faunistic data will be incorporated and made available by the Environmental Information System é SinBiota/FAPESP.Universidade Federal de Minas GeraisA famılia Chironomidae constitui um grupo importante de Diptera aquötico, pois participa significativamente da composic ao da comunidade de macroinvertebrados bentÕnicos dos mais variados tipos de sistemas aquöticos. Estima-se pelo menos 2.000-3.000 espàcies por regiao biogeogröfica. Entretanto, no Brasil, os trabalhos sobre ecologia e taxonomia sao escassos. No Estado de Sao Paulo, foram registrados somente 89 generos e 66 espàcies. Para contribuir no enriquecimento do conhecimento desta famılia, este trabalho teve como objetivo estudar a fauna de Chironominae no Parque Estadual de Campos do Jordao, pela inexistencia de dados para esta famılia na regiao e por apresentar caracterısticas peculiares para o Estado de Sao Paulo como: altitude elevada e clima subtropical de altitude (temperado). As amostras dos imaturos, utilizando-se amostrador tipo Surber e Rede em D , foram realizadas nos corregos Galharada e seu afluente, Campo do Meio e Casquilho, todos de baixa ordem, com leito pedregoso e protegido pela vegetac ao ripöria; suas öguas sao transparentes, frias, bem oxigenadas, öcidas, com valores de condutividade elàtrica e turbidez baixos. Os adultos foram capturados proximos aos pontos de coleta das larvas utilizando-se armadilha luminosa. Os resultados mostraram diferenc as na estrutura da comunidade de larvas entre os corregos. Atravàs das anölises, pode-se constatar o agrupamento dos pontos do corrego Galharada, situados numa regiao central do parque e representados principalmente pelos töxons aff.Omisus sp1 e Corynoneura. Jö os pontos dos corregos Campo do Meio e Casquilho, sujeitos a perturbac es antropicas, apresentaram domin ncia da espàcie aff. Pseudochironomus sp1. Os exemplares adultos apresentaram diversidade superior á das larvas, sendo registradas novas ocorrencias para o Estado de Sao Paulo (Neelamia e Paramerina), bem como novas espàcies (Antillocladius sp1 e Goeldichironomus sp). Os dados faunısticos serao incorporados e disponibilizados atravàs do Sistema de Informac ao Ambiental é SinBiota/FAPESP

Structure of benthic macroinvertebrate assemblages on a gradient of environmental integrity in Neotropical streams

AIM: This study investigated the taxonomic composition of the benthic macroinvertebrates in streams to evaluate how this fauna reflects the various uses of the soil and to identify which groups of macroinvertebrates might be taken as characterizing each situation under study. METHODS: To achieve these objectives, 29 streams were collected and inserted in regions with different conservation using Surber sampler. Analyzes were performed of environmental variables (Principal Components Analysis - PCA) and taxonomic structure of the community (taxon richness, numerical abundance and Multidimensional scaling - MDS). RESULTS: EPT group (orders Ephemeroptera, Plecoptera and Trichoptera) and the Coleoptera exhibited greater numerical abundance and taxon richness in streams located in reference areas. In contrast, dipteran larvae, especially the chironomids, along with immature odonates, were more abundant in streams in areas suffering from a lack of riparian forest. Multidimensional scaling analysis (MDS) revealed an environmental gradient, on which the streams within the Atlantic forest formed a tightly clustered group, as did those in semideciduous forests. However, the latter group occupied an intermediate position between the Atlantic forest streams and those in areas disturbed by human activity. Among these areas there were no specific clusters by monoculture. CONCLUSIONS: Among the groups of streams defined by the types of land use in the adjacent areas, the state of integrity was found to decline from Atlantic rainforest, through semi-deciduous forest and then pasture, to the monocultures of eucalypts and sugarcane

Choice of macroinvertebrate metrics to evaluate stream conditions in Atlantic Forest, Brazil

The development of biomonitoring programs based on the macroinvertebrate community requires the understanding of species distribution patterns, as well as of the responses of the community to anthropogenic stressors. In this study, 49 metrics were tested as potential means of assessing the condition of 29 first- and second-order streams located in areas of differing types of land use in So Paulo State, Brazil. Of the sampled streams, 15 were in well-preserved regions in the Atlantic Forest, 5 were among sugarcane cultivations, 5 were in areas of pasture, and 4 were among eucalyptus plantations. The metrics were assessed against the following criteria: (1) predictable response to the impact of human activity; (2) highest taxonomic resolution, and (3) operational and theoretical simplicity. We found that 18 metrics were correlated with the environmental and spatial predictors used, and seven of these satisfied the selection criteria and are thus candidates for inclusion in a multimetric system to assess low-order streams in So Paulo State. These metrics are family richness; Ephemeroptera, Plecoptera and Trichoptera (EPT) richness; proportion of Megaloptera and Hirudinea; proportion of EPT; Shannon diversity index for genus; and adapted Biological Monitoring Work Party biotic index.FAPESP The Sao Paulo State Research FoundationCAPES Coordenação de Aperfeiçoamento de Pessoal de Nível Superio