not a species from Argentina:
Pseudoplatystoma fasciatum (Linnaeus, 1766)

López et al. (2003) listed Pseudoplatystoma fasciatum fasciatum for Argentina following earlier authors (Ringuelet & Arámburu 1961, Ringuelet et. al. 1967, López et al. 1987). All former subspecies are now recognized at species level and P. fasciatum is restricted to the Guyana region. The species found in Argentina is Pseudoplatystoma reticulatum.

published in:
Buitrago-Suárez, U.A. & B.M. Burr (2007):
Taxonomy of the catfish genus Pseudoplatystoma Bleeker (Siluriformes: Pimelodidae) with recognition of eight species.
Zootaxa 1512: 1–38

remarks (from publication):
Pseudoplatystoma fasciatum was considered a widespread species in classical works (e.g. …Ringuelet et al., 1967…) with a range embracing each major river in the neotropics… As recognized here, the genus contains at least 8 species: P. fasciatum restricted to the Guyana region…Eigenmann and Eigenmann (1888, 1889) described four subspecies of P. fasciatum from the Amazon basin; P. f. brevifile, P. f. nigricans, P. f. intermedium and P. f. reticulatum… Eigenmann and Allen (1942), Ringulet et al., (1967) and Mees (1974) placed these names in the synonymy of P. fasciatum

geographic distribution (from publication):
Guyana region, including the Essequibo and Suriname rivers and their tributaries, in the countries of Guyana, Suriname, and French Guiana (Guyana).

abstract (from publication):
The genus Pseudoplatystoma Bleeker consists of three species long recognized as: P. fasciatum (Linnaeus), P. tigrinum (Valenciennes), and P. corruscans (Spix & Agassiz), and five species recently recognized or described here: P. punctifer (Castelnau), P. reticulatum Eigenmann & Eigenmann, P. orinocoense n. sp., P. metaense n. sp., and P. magdaleniatum n. sp. The eight species form a monophyletic group with two clades that are supported by anatomical features (i.e., skeletal anatomy and myology). One clade (P. tigrinum and P. metaense) is restricted to the Orinoco and Amazon basins, and the other clade, comprised of the remaining six species, is found in the Guyanas, Orinoco, Amazon, and Paraná basins.
The species are diagnosed on the basis of body shape, color pattern (e.g., bars, loops, and spots), skeletal anatomy, and vertebral numbers. Pseudoplatystoma punctifer and P. tigrinum are sympatric in the Amazon Basin, P. metaense and P. orinocoense in the Orinoco Basin, and P. corruscans and P. reticulatum, are sympatric in the Paraná. Pseudoplatystoma magdaleniatum (Magdalena basin) and P. fasciatum (Guyanas) each occur as the only species of Pseudoplatystoma in their respective individual ranges. Pseudoplatystoma reticulatum may be sympatric with the two other species in the Amazon Basin, but we have no records of them being captured together in the mainstream or tributaries. All eight species are used as food in both commercial and subsistence fishing, and there is a moderate–sized ornamental fish market for the young and juveniles. A key to adults of the eight species is included.