ROTIFER ASSEMBLAGES - A CONTRIBUTION TO THE TYPOLOGY OF SPANISH RESERVOIRS

An extensive survey of 100 reservoirs on the Iberian peninsula was car ried out in 1987/88. Based on physical, chemical and biological data, several groups of reservoirs were differentiated. To contribute to the zooplankton component of this typology, we studied the species compos ition of rotifer communities from each reservoir. Data from all reserv oirs were integrated separately (stratification and mixing periods) in a principal components analysis. No distinct communities were evident for the different reservoir types, suggesting that each type contains a series of rotifer assemblages, with gradual changes in species comp osition occurring in response to changes in environmental conditions.