Taxonomy & naming
Anduzedoras oxyrhynchus was described by Achille Valenciennes in 1821, making it one of the earlier-named doradids. It has passed through several generic placements typical of the heavily reshuffled thorny catfish family — material now referred to Anduzedoras has at times circulated under other Doradidae genus names, and at least one nominal species once treated separately, Doras lipophthalmus (Kner, 1855), described originally in the genus Rhynchopelates, is now recognised as a junior synonym of this species. The Catalog of Fishes (Eschmeyer, California Academy of Sciences) is the governing authority for the current combination Anduzedoras oxyrhynchus, and that is the name used here.
The genus Anduzedoras belongs to the family Doradidae, the thorny or talking catfishes, a large South American group defined by a lateral line of enlarged, often hook-bearing scutes and by their ability to produce sound. The species epithet oxyrhynchus is a compound of Greek roots (oxys, "sharp" + rhynchos, "snout"), referring to the pointed snout profile typical of the genus.
Morphology
This is a mid-sized doradid, reaching at least 12.5 in standard length. Like other thorny catfishes it carries a row of large, keeled lateral scutes running from behind the head to the tail, and its dorsal and pectoral fins each open on a stiff, coarsely serrated spine that locks erect and cannot easily be folded down once a fish feels threatened. Those same spines can be rubbed against the pectoral girdle to produce the rasping "squeak" or "talking" sound doradids are named for.
The body is elongated with a pointed snout (reflected in the epithet oxyrhynchus) and three pairs of barbels typical of the family, used to feel out food on the riverbed in low light. The skin between the scute rows is naked rather than fully scaled, a trait shared with catfishes generally that has direct consequences for medicating the species (see "In the aquarium").
Habitat
Anduzedoras oxyrhynchus is native to South America, recorded from the Rio Negro and the upper Orinoco River basin, spanning Brazil and Venezuela. It is a tropical freshwater fish of demersal habits, living on or near the bottom of these blackwater and clearwater river systems rather than in open water.
As with most doradids, it forages and rests along the riverbed by day and becomes more active after dark, a pattern that should guide how it is kept and fed in the aquarium. Specific published water-chemistry parameters for the species are sparse in the available sources; as a Rio Negro/upper Orinoco fish it can be expected to tolerate the soft, often tannin-stained water typical of that region, but this should be treated as a general regional inference rather than a directly cited figure.
Feeding
Anduzedoras oxyrhynchus is a nocturnal, benthic omnivore in keeping with the rest of the Doradidae: it forages the substrate mainly after dark for detritus, small invertebrates and other opportunistic food items rather than hunting actively in open water.
In the aquarium this translates into a fish that does best on sinking pellets, frozen foods and other prepared foods offered once the lights are out or the tank is dim, so it is not out-competed by more visible, day-active tankmates. Given its adult size, feeding should scale accordingly, and larger specimens will take correspondingly larger sinking foods.
Mating
No species-specific account of courtship or spawning behaviour for Anduzedoras oxyrhynchus is available in the sources consulted here. Breeding biology in Doradidae is not uniform across the family, so a mode should not be assumed for this species; data on its reproductive behaviour is sparse.
Breeding
Anduzedoras oxyrhynchus is not documented as bred in home aquaria in the sources consulted here, and no aquarium spawning reports are available. Given its size and the general pattern among larger Doradidae — most of which are not reproduced by hobbyists and, where propagated at all, are handled at a commercial or research scale — it should be treated as effectively unbred in the home aquarium until better evidence emerges. Stocked fish are wild-collected.
In the aquarium
The single most important care fact for this species is its size: Anduzedoras oxyrhynchus reaches at least 12.5 in standard length, well past the point where it can live out its life in anything but a large tank. Prospective keepers should plan for a substantial aquarium from the outset rather than assuming it will stay small — the size trap is the most common way large catfish end up outgrown, rehomed or neglected.
Two further points follow directly from its biology as a doradid. First, its skin is naked between the scute rows, so like scaleless fishes generally it is medication-sensitive — copper-based treatments and many other medications should be dosed conservatively, often at reduced strength, as is standard practice for loaches, puffers and other naked-skinned catfish. Second, it carries stiff, serrated, locking pectoral and dorsal spines that readily snag in a net and can jab the handler; it should always be moved in a container rather than netted, and care is needed during any tank maintenance. It is a nocturnal fish and appreciates cover such as caves, pipes or dense structure to retreat into during the day, becoming more visible once the lights go down.
Conservation
The IUCN Red List assesses Anduzedoras oxyrhynchus as Least Concern, reflecting a wide native range across the Rio Negro and upper Orinoco basins without evidence of significant population decline.
As with many South American blackwater and river fishes, longer-term pressures in its range include habitat disturbance and water-quality changes tied to development along the Rio Negro and Orinoco systems, though the species is not currently flagged as threatened. Aquarium specimens are understood to originate from wild collection rather than captive breeding.