Short-term variability of copepod abundance in Jurumirim Reservoir, São Paulo, Brazil

摘要: Short-term variability in composition and abundance of copepod populations were studied during the dry (winter) rainy (summer) seasons, at dam region Jurumirim Reservoir, Sao Paulo, Brazil. An intensive sampling program was carried out 30 days each period year. Samples measurements taken every other day 0, 5, 10, 15, 20 25 m depths. The relationship between some environmental factors analyzed. main species were: Argyrodiaptomus furcatus (Sars), Notodiaptomus iheringi (Wright), Mesocyclops longisetus (Thiebaud), Thermocyclops decipiens (Fischer), T. minutus (Lowndes). most abundant season its varied significantly days. A large increase calanoids occurred season. This correlated with higher temperature values. At that time, dominant. showed significant short-term variations both seasons. Significant variation density within same might result from either dispersion pattern or continuous substitution water masses. correlation observed temperature, especially for there also correlations densities particular copepods phytoplankton taxa, mainly As vertical distribution, organisms found surface 15 deep. During season, evidence occurrence spatial segregation cyclopoids calanoids, a deeper position column.