Taxonomy & naming
The species was described in 2018 by Espíndola, Tencatt, Pupo, Villa-Verde and Britto in the Journal of Fish Biology, in a paper subtitled 'from the inside out' for its emphasis on poorly explored internal character sources — chiefly the skeleton — alongside the usual external features. Its type locality is the Rio Culuene, a tributary of the Rio Xingu between Canarana and Gaúcha do Norte in Mato Grosso, Brazil. The hobby had already been keeping it for years under the code C022, so the formal description put a name to a familiar fish.
It was placed in the huge genus Corydoras Lacépède, 1803 (family Callichthyidae). That genus had grown to well over 170 species and molecular work showed it was not a single natural group, so the 2024 revision by Dias, Tencatt and colleagues split it into several genera — Brochis, Hoplisoma, Gastrodermus, Osteogaster and others. Under that scheme the species becomes Hoplisoma benattii. We keep the familiar heading 'Corydoras benattii', under which it is traded and written about, while noting the current combination. The specific name honours the collector and aquarist associated with the material rather than describing the fish.
Morphology
This is a small cory, reaching only about 1.5 in in standard length; females grow larger and fuller-bodied than males, a difference seen best from above, and mature males tend to have more pointed fins. Like all Corydoradinae it is armoured rather than scaled, with two overlapping rows of bony scutes down each flank, a hard helmet-like head and three pairs of short barbels around the downturned mouth.
Its colour pattern is a dense, fine dark speckling — hence 'speckled Xingu cory' — scattered over a pale ground, without a single bold blotch or stripe, which is part of why it was long confused with similar small spotted corys of the region. Much of what distinguishes it from those look-alikes lies inside: the original description leaned on osteological details to separate it. The dorsal, pectoral and adipose fins each bear the usual stiff, mildly venomous leading spine.
Habitat
Corydoras benattii is a fish of the southern Amazon clearwater rivers, distributed across the Xingu and Tapajós basins (including the Teles Pires and Cururu drainages) in central Brazil. These are classic clearwater systems draining the old, eroded uplands of the Brazilian Shield — warm, often fast and rocky in their main channels but with the sandy margins, backwaters and leaf-littered creek mouths that corys favour.
Reported aquarium temperatures of roughly 72–79 °F reflect the warm, clear conditions of its range; the water is generally soft and close to neutral. Like other corys it is a facultative air-breather, rising to the surface to gulp air and absorb oxygen through a vascularised hindgut — an adaptation for warm, shallow, oxygen-variable waters.
Feeding
The speckled Xingu cory is a benthic omnivore and detritivore, working the sandy bottom continuously and burying its snout and barbels to taste out small invertebrates, insect larvae, worms and organic detritus, passing cleaned sand out through the gills. In the aquarium it readily takes sinking tablets, granules and larger flakes, along with live and frozen foods such as bloodworm, white worm, grindal worm, Daphnia and Tubifex, the richer of which are useful for conditioning a group before spawning. As with all corys it should not be left to scavenge leftovers alone.
Mating
Corydoras benattii is an egg-laying shoaler with the family's characteristic 'T-position' courtship and no pair bond. A ready female cleans a spawning site, the group grows active, and a male places himself at right angles to her head; she appears to take his milt at the mouth, sperm is thought to pass quickly through her gut to fertilise the few eggs held in a basket of her clasped pelvic fins, and she presses them onto the cleaned surface. The cycle repeats a few eggs at a time. Detailed spawning observations specific to this species are limited, and this account follows the well-documented pattern of its close relatives.
Breeding
The original description and subsequent hobby reports indicate the species has been bred in aquaria — fry development was illustrated under aquarium conditions in the describing study — but a full, widely replicated breeding protocol is not established. By the standard Corydoradine pattern it would be triggered by a cool, generous water change mimicking the rainy season, lay small batches of adhesive eggs on firm surfaces, and give no parental care, with adults apt to eat the eggs unless eggs or parents are separated. Eggs of related corys hatch in roughly three to five days, and fry take microworm, baby brine shrimp and powdered foods after absorbing the yolk. We note the documented fry development while flagging that a reliable step-by-step protocol is still thin.
In the aquarium
An attractive, modestly sized cory for the community or biotope tank, Corydoras benattii needs the same essentials as its relatives. It is a shoaling species, genuinely stressed when kept alone or in twos — keep six or more for confident, busy behaviour. A group is comfortable in a tank of around 23.5 in or more, where bottom area matters more than height.
Substrate is close to mandatory: soft sand or very smooth fine rounded gravel, never sharp or coarse grit, which erodes and infects the barbels corys use to feed. Border an open feeding area with driftwood and planting and provide some shade. Suit the water to its clearwater origins — warm (about 72–79 °F), soft, near-neutral, well-filtered and well-oxygenated, with regular changes. It is wholly peaceful and ideal with tetras, pencilfish, dwarf cichlids and other calm community fish; avoid boisterous or large tankmates. Net with care, as the fin spines snag, and transport gently, since a stressed cory can release skin toxins that may kill the group in the small volume of a bag.
Conservation
Corydoras benattii has not been assessed by the IUCN Red List, so its conservation status is formally Not Evaluated. It appears reasonably widespread across the Xingu and Tapajós basins, which argues against immediate concern, but those very rivers are among the most heavily impacted in Amazonia: the Xingu is dammed by the vast Belo Monte complex, and both basins face hydropower expansion, deforestation, agricultural run-off and mining. Such pressures fall directly on the clearwater habitats this species depends on. As an unassessed but commercially collected fish, it would benefit from a formal Red List evaluation and from monitoring of the basins it occupies.