Another Oiapoque fish, maybe not a catfish....

[Mocotun]

Here is another one that no one has been able to ID yet. It was caught and released from the narrow creeks off the Rio Oiapoque in Northern Brazil. It readily attacked lures and bait. Someone suggested it was a Firewood Catfish. It's pectoral fins look catfish-like. It's barbless, like the Palmito catfish common in Brasil and measured no more than a foot long.

[Marc van Arc]

This is a catfish, a kind of Palmito or Bocon as they say in Peru.
It is an

Ageneiosus

species, but due to the angle of the picture it is difficult to say which one exactly.

[Marc van Arc]

Addition: given the location it could well be

Ageneiosus marmoratus

. Click the link and have a look at the adult specimens as the juveniles look quite differently.
Also bear in mind that freshly caught fishes like these have a yellowish glow and look lighter than specimens that are kept in a tank, most likely because we are not able to provide them with a 100% "natural" environment.

The Firewood catfish

Sorubimichthys planiceps

has large whiskers. Ageneiosus do have whiskers, but they are very small.

[Viktor Jarikov]

It is definitely a woodcat, the type of the bottle-nose catfish, dolphin/whale catfish, etc. known by many names. They are highly predatory and have a huge mouth for their size. Marc is an expert in these fish.

This is definitely not a Pimelodidae, not the planiceps.