not a species from Argentina:
Heptapterus collettii Steindachner, 1881

published in:
Bockmann, F.A. & M.C.C. de Pinna (2004):
Heptapterus collettii Steindachner, 1881: A member of the asian bagrid genus Olyra erroneously assigned to the neotropical fauna (Siluriformes: Ostariophysi).
Copeia 2004 (3): 665–675.

abstract (from publication):
Heptapterus collettii Steindachner, 1881, a catfish described from La Plata basin in South America, has a puzzling set of characters for Neotropical siluriforms. Examination of one syntype shows that H. collettii does not belong to Heptapteridae or any other Neotropical family but rather to Olyra, a genus of Bagridae endemic to South Asia. Thus, it should be referred to as Olyra collettii. The species has nasal barbels on the posterior nares (shared with various Old-World catfish taxa), a wide separation between the anal and urogenital openings (shared with a large subgroup of Bagridae) and a unique structure of the first lateral-line ossicle (shared with species of Olyra). The species is similar to Olyra longicaudata, although there are significant morphometric and meristic differences. Current problems in the taxonomy of Olyra prevent conclusive resolution of the identity of O. collettii. The presence of a species of Olyra in South America is unlikely, and we consider this to be a result of mistaken locality records.

In the past the species was reported as from Argentina under Heptapterus collettii (by Pozzi 1945) or Myoglanis collettii (by Ringuelet et al. 1967; Lopez et al. 1987, 2003).