PENCZAK, Tadeusz; GODINHO, Francisco; AGOSTINHO, Angelo Antonio. Verification of the dualism ordering method by the canonical correspondence analysis: fish community samples. Limnologica, Jena, v.32, no.1, p.14-20, 2002.Two ordination techniques (Romaniszyn diagram, RD, and Canonical correspondence analysis, CCA) were applied to the same data set (fish assemblage composition along two Paraná river tributaries and associated environmental variables), to identify spatial community patterns and further to evaluate the performance of RD. The major patterns in these Brazilian streams were successfully revealed by both methods (i.e. clear separation of both tributaries on the basis of fish assemblage composition and environmental factors), but more complex situations may limit the application of RD in comparison with CCA.