confirmed as a species from Argentina:
Crenicichla iguassuensis Haseman, 1911

published in:
Casciotta, J, A. Almirón, L. Ciotek, P. Giorgis, O. Říčan, L. Piálek, K. Dragová, Y. Croci, M. Montes, J. Iwaszkiw & A. Puentes (2016):
Visibilizando lo invisible. Un relevamiento de la diversidad de peces del Parque Nacional Iguazú, Misiones, Argentina.
Historia Natural 6 (2): 5-77

abstract (from publication):
The aim of this study is to survey the fish fauna of the Iguazu National Park and designate those vulnerable species with special value (EVVES). As a result of this project 104 species were recorded, of which 28 are endemic to the basin and 13 represent new records for Argentina. Finally, 87 species of PNI with special value representing 83% of total fish recorded were identified.

remarks:
Casciotta (1987, description C. celidochilus) listed comparative material from both, the Río Iguazú and the Arroyo Urugua-í, as C. cf. iguassuensis. Casciotta et al. (2006, description C. yaha) informed that the specimens included in Casciotta (1987) as C. cf. iguassuensis represent members of two then yet indescribed species. Pialek et al. (2016, descriptions of C. tapii and tuca) include specimens of C. iguassuensis in their study with the restriction that the “taxonomic status of the populations referred to here as C. iguassuensis remain tentative” and that “the Argentinean populations may indeed be a distinct species… from C. iguassuensis”.
Hence, the now presented specimens of this species from Argentina seem to be the first ones assigned to C. iguassuensis without restriction.