A sample collected from rice-fish fields (Oriza sativa L. and Cyprinus carpio Linnaeus, 1758) in shallow water (20 m²× 0.30 m deep) in the Itajai River Valley region, Santa Catarina (26º53'33''S and 48º49'41''W) revealed 48 morphospecies from the class Euglenophyceae represented by the genera Euglena, Lepocinclis, Phacus,Strombomonas and Trachelomonas. Trachelomonas was the best represented genus with 26% of all taxa. The reddish water at the time of sampling was due to the high number of Euglena caudata Hübnerand Euglena sanguinea Ehr. individuals per plate (bloom). Twenty eight taxa are new records for the state of Santa Catarina. Descriptions, dichotomous keys, size variation, length/width relationship (Rc/l), illustrations and geographic distribution are provided for all taxa.
rice fields; phytoplankton; Euglena sanguinea; Itajaí; southern Brazil
