Taxonomy & naming
Gladys' cory was described in 2010 by Pablo Calviño and Felipe Alonso, in a paper in the Revista del Museo Argentino de Ciencias Naturales that named two new Corydoras from northwestern Argentina and redescribed C. micracanthus Regan, 1912. It was placed in Corydoras Lacépède, 1803, the large genus of South American armoured catfishes (family Callichthyidae, subfamily Corydoradinae). The species name honours Gladys Ana María Monasterio de Gonzo, the ichthyologist at the Universidad Nacional de Salta who first collected the fish.
Like the rest of the genus, it was caught up in the 2024 phylogenomic revision by Dias, Tencatt and colleagues (Zoological Journal of the Linnean Society), which split the overgrown Corydoras into several genera. Under that classification Gladys' cory becomes Hoplisoma gladysae, the combination now used by Eschmeyer's Catalog of Fishes and FishBase. The change is recent and not yet universal, so we retain 'Corydoras gladysae' as the heading while recording the current valid combination. C. gladysae belongs to a small cluster of corys endemic to the upper Paraná headwaters of subtropical Argentina, alongside relatives such as C. micracanthus and C. petracinii.
Morphology
This is one of the smaller corys, reaching only about 1.5 in in standard length. The body is the familiar corydoradine form — short, fairly deep, flat-bellied and armoured with two overlapping rows of bony plates rather than scales, with a blunt helmeted head and a small, downturned, barbel-fringed mouth.
In the formal description the species is distinguished from its congeners chiefly by fin proportions rather than colour: it has notably short dorsal and pectoral-fin spines (averaging roughly 9 and 15 percent of standard length, respectively) and a slightly emarginate (gently notched) caudal fin. The coloration is a modestly patterned grey-brown over a paler ground, in keeping with the subdued, well-camouflaged look of the high-altitude Argentine corys. As is usual in the group, the dorsal, pectoral and adipose fins bear stiff leading spines, and mature females are expected to be larger and broader than males, though detailed dimorphism has not been emphasised for this species.
Habitat
Corydoras gladysae is known only from the Calchaquí River around the localities of Cachi and Payogasta, in the Cachi Department of Salta province, in the sub-Andean ranges of northwestern Argentina. This is a strikingly atypical setting for a cory: the type locality lies at roughly 2,400 metres above sea level, in cool, clear, fast-flowing Andean foothill water rather than the warm, sluggish lowland streams most of the genus inhabits. The Calchaquí drains into the upper Juramento River system, which in turn feeds the Paraná basin, so despite its mountain home the species belongs ultimately to the great La Plata–Paraná drainage.
Because it is a high-altitude subtropical fish, the relevant water is cooler and better-oxygenated than typical tropical cory habitat, and aquarists who have kept the related upland Argentine corys note they prefer temperatures toward the lower end of the genus's range. Detailed published water-chemistry figures for the wild habitat are limited, so we are honest about that gap rather than inventing precise numbers; what is clear is that this is a cool, running-water, headwater species rather than a warm-lowland one.
Feeding
No species-specific dietary study has been published, but Gladys' cory is, like all corydoradines, a benthic omnivore and detritivore. It works the bottom of its stream, sifting fine sediment with its barbels to extract small invertebrates, insect larvae, micro-crustaceans and organic detritus, and expelling cleaned substrate through the gills. In the rare event of being kept in captivity it would be expected to take the standard cory fare — sinking pellets and granules, frozen and live bloodworm and brine shrimp — but as a small, cool-water species it has no special feeding requirement beyond clean substrate to forage over.
Mating
Spawning behaviour has not been documented for Corydoras gladysae specifically. It can be assumed to follow the corydoradine pattern: an egg-laying shoaler with no pair bond, in which a receptive female cleans a site, a male adopts the 'T-position' at right angles to her head, and the female cradles a few eggs at a time in a pelvic-fin basket before pressing them onto a firm surface. The classic interpretation has the female briefly taking milt into her mouth so that sperm passes through the gut to fertilise the clutch. Given the species' cool, high-altitude home, any spawning is likely cued by seasonal changes in temperature and flow rather than the warm rainy-season triggers used for lowland corys.
Breeding
There is no aquarium breeding record for C. gladysae — it is effectively unknown in the hobby, and the fish in collections are scientific specimens rather than trade stock. By analogy with other corys, it would be an egg-scatterer laying small batches of adhesive eggs on firm surfaces, with no parental care and a tendency for adults to eat the eggs, so a breeder would remove eggs or parents. Eggs of small corys typically hatch within a few days and the fry take microworm, baby brine shrimp and powdered foods. For this particular species, though, the honest position is that its reproduction has not been observed or described.
In the aquarium
Gladys' cory is essentially not an aquarium fish — it is a narrowly distributed, recently described species kept by scientists rather than hobbyists, and it does not enter the trade. Were it ever maintained, its needs would differ from a typical lowland cory in one important respect: as a high-altitude Andean-foothill fish from cool, fast, well-oxygenated water at around 2,400 metres, it would want a cooler tank (toward the lower end of the cory range), strong oxygenation and gentle current, rather than warm tropical conditions. Otherwise the general rules apply: keep corys in groups of six or more, provide soft sand or smooth fine gravel to protect the barbels, keep the substrate clean, and pair them only with small, peaceful tankmates. We flag this section as largely inferential, since there is no body of keeping experience for the species to draw on.
Conservation
Corydoras gladysae has not been assessed by the IUCN, so it carries no Red List category. That gap is itself worth noting: the species is known from only two localities on a single high-altitude river, the Calchaquí, in Salta province, which makes it a textbook narrow endemic and exactly the kind of fish whose status would warrant careful evaluation. High Andean-foothill streams of this sort are vulnerable to water abstraction for agriculture, to changes in flow, and to the introduction of non-native fishes, all of which can press hard on a species with so small a known range. Until a formal assessment exists, its conservation status is best described honestly as unknown.