This species’ name is commonly misapplied to a number of similar-looking fishes and it can be difficult to identify if collection locality is unknown. In addition, colour pattern is variable and it’s not clear whether this occurs between, within, or both between and within populations.

In the original description, Steindachner did note that the first three dorsal-fin rays are completely black while the remainder is whi…

The most obvious distinguishing characters are that the black marking in the upper part of the body is restricted to the area beneath the dorsal-fin and extends into the majority of the fin , while the paler patch anterior to it, on top of the head, is yellowish rather than orangish.

Additional diagnostic characters have proven unavailable thus far since it was described in a hobbyist magazi…

Type locality is given as ‘Small tributary of the upper Rio Negro on the equator near São Gabriel da Cachoeira, Brazil’, and this species is apparently highly endemic there.

Some sources state that it also occurs in the rio Uaupés (known as ‘Vaupés’ in Colombia), a major tributary of the Negro, but we’ve been unable to obtain confirmation thus far.

This species is among the more popular Corydoras in the aquarium hobby and is widely available. It may also be referred to as ‘arched cory’.

There exist a number of similar-looking congeners, particularly C. urucu (Britto et al., 2009), described from the rio Urucu in Coari municipality, Amazonas state, Brazil, and C. narcissus from the rio Purus. The latter appears to have also been traded as C. sp. ‘super arcuatus longnose’ while a larg…

Despite the ubiquity of its name in aquarium literature, confusion surrounds its true identity. Given it’s the only member of the genus occurring on the island, fish from Trinidad do presumably represent C. aeneus (see our image), but the classification of those from other localities appears far from certain.

Today the species is accepted to occur throughout much of South America, and indeed similarly-patterned fish do occur across a large portion of the continent. Some of these, such as the gree…

This species is sometimes confused with B. juruense, especially when juvenile, but can be told apart quite easily by it’s more well-defined colour pattern, relatively slender body shape and longer barbels. It was described in the genus Meredontotus, but is currently included in Brachyplatystoma based on a pair of synapomorphies shared by memb…

Brachyplatystoma spp. are distinguished from all other catfishes by two synapomorphies. The first comprises several morphological characters relating to the skull, specifically that the mandibular suspensorium (that which connects the lower jaw bone to the skull) is greatly expanded mediodorsally to form a large plate approaching the parasphenoid bone, with the hyomandibula and metapterygoid similarly enlarged.