The depth as a factor in determining annual change density of macroinvertebrates associated with Salvinia auriculata Aublet

Abstract

The aim of this work was to study the effects of water annual variation of Paranapanema River and others variables on macroinvertebrates that lives in macrophytes roots, from March 2006 to February 2007. The sampled was realized with a hand-net (mesh size: 0.25 mm) and 0.07 m2 circle area. We measured air and water temperature, depth, dissolved oxygen, pH, K25  and suspended matter. The normality was tested and a Canonical Correspondence Analysis (CCA) was realized. Telebasis showed high density in period studied. There was a high variation in depth: 6.07 m in  April 2006 to 1.83 m in November 2007. The CCA showed that Culicidae, Ephemeroptera, Ostracoda, Calopterygidae, Coryphaeschna and Cyanallagma were significative correlated with the depth. We concluded that the effect of the depth on larvae Odonata can not have been direct, but indirect by the effect in your substrate as aquatic plant.