Helogenes marmoratus is a species of whale catfish occurs in Brazil, Ecuador, French Guiana, Guyana, Peru, Suriname and Venezuela.

[1] It is a typical inhabitant of black or clear waters, usually in forest streams with moderate to swift current flow over firm sand or gravel bottoms .

[2] It can easily be mistaken as a piece of dead wood when it rests on its side, motionless on the bottom.

[1] When disturbed, H. marmoratus will move upwards through the root-tangle, exposing its head or fore body above the water surface.

If disturbed further, it will quickly swim in an upright position towards the nearest debris shelter.