Description of a new species of Diaptomidae (Crustacea, Copepoda, Calanoida) Notodiaptomus oliveirai is given from the material obtained at a reservoir at Barra Bonita, SP in 1992. The new species is very similar to Notodiaptomus henseni Dahl 1894 although both species can be found in the same locality, constituting two distinct populations. Notodiaptomus oliveirai seems to be endowed with great adaptability to changes in environmental conditions, extending its distribution to all the hydrographic basins in the state of São Paulo.
new species; Brazil; Notodiaptomus oliveirai; geographical distribution; São Paulo State
