This species appears endemic to and abundant within the upper Suriname River system, Suriname.

Type locality is given as ‘little tributaries of Gran Rio between Ligolio and Awaradam Falls’, this corresponding to a section of the Suriname River, which is known as ‘Gran Río’ in parts of its upper basin, upstream of Brokopondo reservoir and not…

C. aurofrenatus is currently understood to occur throughout much of the Río Paraguay-Paraná system in Paraguay, and has also been recorded in Argentina and Bolivia.

It was described from Paraguay with type locality given as ‘Aguada near Arroyo Trementina’. The latter is stated to be a tributary of the ‘Rio Aquido Canigi’.

C. amandajanea is rare in the aquarium trade and appears to be variable in colour pattern to an extent, with some individuals posssessing relatively larger dark spots on the body, for example.

Unfortunately diagnostic characters cannot be provided since we’ve been unable to obtain the type description, and little has been written about this species since it was published.

In the upper Iténez it most commonly inhabits riparian zones with sandy substrates or edges of sand banks, although it’s also been collected in smaller streams and residual flood waters.

It typically forms large aggregations of up to several thousand individuals and at the confluence of the ríos Paraguá and Iténez occurs sympatrically with the congener C. paragua.

This species can be confused with three similar-looking fishes of uncertain taxonomic status which have been assigned the C numbers C024, C077, and C109 in the aquarium hobby.

C024 and C109 are unlikely to be conspecific in that they occur in Pará state, Brazil, several thousand kilometers outside the range of C. acutus, in the rio Guamá (Tocantins drainage), and lower rio Xingu, respectively.

Type locality is ‘Furo do Lago São Francisco, 7°40’S, 72°39’W, tributary at left bank of Rio Juruá, Acre State, Brazil’, and C. acrensis appears to be endemic to the rio Juruá basin.

Unfortunately diagnostic characters cannot be provided since we’ve been unable to obtain the type description, and little has been written about this species since it was published.

This species is sometime referred to as ‘Virginia’s catfish’, Corydoras sp. ‘Sangama’ or ‘Zangama’, and prior to description was misidentified as both Corydoras bicolor and C. delphax.

Unfortunately additional diagnostic characters cannot be provided since we’ve been unable to obtain the type description, and little has been written about this species since it was published.

This species can be identified from similar-looking congeners by possession of a pair of small rictal barbels.

Its colour pattern can vary considerably depending on collection locality, with some forms having been misidentified as other species in the past. Those possessing a dark marking on the sides of the body are sometimes referred to as Corydoras sp. ‘olga’.

The form from the Río Tigre, previously referred to as the subspecies C. p. orcesi (Weitzman & Nijssen, 1970) was raised to full species status as C. orcesi by Isbrücker (2001), but this decision does not appear to have been followed by all authorities some of which consider C. p. orcesi a synonym of C. pastazensis.

The two species are relatively easy to tell apart by colour pattern; in C. pastazensis the dark vertical…

C. incolicana was the first recipient of a ‘C’ number (see below) in 1993 and was described the same year. Unfortunately its description was published in an aquarium hobbyist magazine, and we have been unable to obtain a copy to date meaning its diagnosis is unavailable. It is therefore difficult to identify accurately, not least because its type locality is in a relatively remote area, and there exist a number of superficially similar Corydoras species or populations in the aquarium trade.