Taxonomy & naming
Hinrich Lichtenstein described the species in 1819, and the parentheses around the authority show that it was first placed in another genus. The Catalog of Fishes lists Calophysus macropterus as valid, with the type locality given only as Brazil. It belongs to the long-whiskered catfish family Pimelodidae, and Calophysus has long been treated as a one-species genus.
Morphology
FishBase gives a maximum length of 15.5 in TL. It is a slender pimelodid with a blunt head and large fins, which the epithet records.
Habitat
FishBase lists the species from the Amazon and Orinoco basins and describes it as a freshwater bottom fish in the tropics, with no temperature or pH range given.
Feeding
FishBase notes that it commonly attacks fishes caught in fishermen's nets and seines and those hooked on trotlines, which fits a scavenging habit. In captivity it needs meaty foods.
Mating
Courtship is not recorded for this species.
Breeding
Breeding is not recorded in FishBase for the species, and it is not known to be bred in aquaria.
In the aquarium
Zamurito appears in the trade rarely and is not suited to a community tank, since it eats small fishes and bites at tankmates. It needs a large, open tank with warm water, but no source gives figures for it, so none are quoted here.
Conservation
IUCN lists the species as Least Concern, assessed in 2020. In Brazil it is caught in large numbers as piracatinga, and its use as bait has been tied to the killing of river dolphins and caimans for carcasses.