Taxonomy & naming
Vaillant described this fish in 1880. The Catalog of Fishes (Eschmeyer, CAS) lists Platysilurus mucosus (Vaillant, 1880) as valid, in the family Pimelodidae, the long-whiskered catfishes. The type locality is the "Upper Amazon at Calderon, Brazil". The genus name combines the Greek platys, flat, with the old catfish name Silurus.
Morphology
FishBase states a maximum length of at least 8 in SL. The body is long and rather flattened, with long barbels, as in other pimelodids. The species name is Latin for slimy.
Habitat
FishBase records a freshwater demersal fish of the Amazon and Orinoco River basins. No temperature, pH or hardness range is recorded, and the source gives no habitat detail beyond the bottom-living habit.
Feeding
FishBase records no diet. Medium-sized pimelodids are bottom-feeding predators on invertebrates and small fish, and in aquaria they take sinking foods, meaty frozen foods and earthworms.
Mating
Courtship and spawning behaviour are not recorded in the available sources.
Breeding
No breeding record is available for this species.
In the aquarium
A tank for a 8 in catfish should be at least 59 in long, with open floor for the long barbels and cover for the day. Keep it with fish that are too large to swallow, because small tankmates will be eaten at night. The source gives no water parameters; soft to moderately hard, clean tropical water suits large-river pimelodids in general. Feed after dark.
Conservation
The IUCN Red List assesses Platysilurus mucosus as Least Concern (assessment of 28 December 2020). It is wide-ranging across the Amazon and Orinoco basins.