Las Tablas de Daimiel National Park is a semiarid, hypertrophic wetland located in La Mancha (Ciudad Real, Central Spain). During the period 1996-2002 we carried out monthly samplings at three sites of Las Tablas. Thirty five taxa of Euglenophytes of the genera Astasia (1 taxon), Euglena (15), Lepocinclis (6), Phacus (9), and Trachelomonas (4) were identified. Six taxa are new records for Spain. Abundance, species richness, species groups and absolute and relative biomass of Euglenophytes widely fluctuated spatio-temporally in Las Tablas, without any statistically significant relationship (P > 0.05) with organic carbon (either particulate or dissolved), which has been long considered the ma…