Invertebrates associated to Eichhornea azurea Kunth in a lagoon of the Upper Paran芍 River: composition, community attributes and influence of abiotic factors Invertebrados associados 角 Eichhornea azurea Kunth em uma lagoa do alto rio Paran芍: composi o, atributos da comunidade e influ那ncia de fatores abi車ticos

作者：Valeria Flavia Batista Silva; Daiane Dias Boneto; Dayani Bailly; Milza Celi Fedatto Abelha

来源：Acta Limnologica Brasiliensia, 2011.

• macrofitas aquaticas
• Chironomidae
• gradientes limnologicos
• ciclo hidrologico
• ambiente lentico
• aquatic macrophytes
• Chironomidae
• limnological gradients
• hydrological cycle
• lentic environment

AIM: We evaluated the composition and community attributes of invertebrates associated to Eichhornia azurea at Cascalho Lagoon, Upper Paran芍 River, Mato Grosso do Sul State, Brazil, over a hydrological cycle, as well the possible influence of abiotic factors upon these attributes. METHODS: The samplings were conducted during 2010 in the rainy and dry periods at stands of E. azurea. The attributes evaluated were abundance, richness, diversity, evenness and dominance. The abiotic factors, temperature, dissolved oxygen, pH and turbidity were summarized by a Principal Component Analysis (PCA). In order to verify possible differences between the mean values of the community attributes and the scores of the PCA axis in different periods, we employed null models analysis of variance. The influence of abiotic factors on each attribute was evaluated through Pearson correlations. RESULTS: We captured 3,052 individuals, distributed into 32 taxa, belonging to the phyllum Mollusca, Annelida, Nematoda and Arthropoda. Among the assessed attributes, only abundance and richness varied significantly between periods, with higher values during the rainy period. Chironomidade was dominant in both periods, whereas Notonectidae and Cyclopoida were rare in the rainy, and Bivalve, Decapoda, Haliplidae, Trichoptera and Pyralidae, in the dry period. A temporal distinction was evident only for the PCA axis 1, which represented gradients in temperature, dissolved oxygen and pH. Among the community attributes, only abundance was significant and negatively correlated with this axis. CONCLUSION: We attested that: i) the rainy period should add favorable conditions for invertebrates%26apos; higher richness and abundance in this macrophyte; ii) only the later attribute was influenced by limnological gradients. OBJETIVO: N車s avaliamos a composi o e atributos da comunidade de invertebrados associados 角 Eichhornia azurea na lagoa do Cascalho, alto rio Paran芍, MS, Brasil, durante um ciclo hidrol車gico, bem como a poss赤vel influ那ncia de fatores abi車ticos sobre estes atributos. M谷TODOS: Amostragens foram realizadas em bancos de E. azurea durante os per赤odos chuvoso e seco em 2010. Os atributos avaliados foram abundancia, riqueza, diversidade, equitabilidade e dominancia. As vari芍veis limnol車gicas temperatura, oxig那nio dissolvido, pH e turbidez foram sumarizadas atrav谷s da An芍lise de Componentes Principais (PCA). Para verificar poss赤veis diferen as entre as m谷dias dos atributos e dos escores do eixo 1 da PCA nos diferentes per赤odos utilizou-se an芍lises de variancia de modelos nulos. A influ那ncia dos f