Taxonomy & naming
Corydoras fulleri was described in 2021 by Luiz Tencatt, André Santos, Hans-Georg Evers and Marcelo Britto in the Journal of Fish Biology, drawn from material in the río Manuripe and a tributary of the río Madre de Dios in the rio Madeira drainage of Peru. The specific name honours Ian Fuller, founder of Corydoras World, for his work on the Corydoradinae. In the hobby the fish had circulated for some time under the provisional collection codes C115 and C116 before the formal description settled its identity.
The species belongs to Corydoras Lacépède, 1803, the large genus of South American armoured catfishes (family Callichthyidae). The 2024 revision of the Corydoradinae by Dias, Tencatt and colleagues split the old all-encompassing Corydoras into several genera, but fulleri is a long-snouted member of the lineage that retains the name Corydoras in the strict sense (Corydoras s.s.), the group anchored on the type species C. geoffroy. So unlike many corys reassigned to Brochis, Hoplisoma, Osteogaster or Gastrodermus, this one stays Corydoras under both the trade and the current scientific usage.
Morphology
Corydoras fulleri is a long-snouted cory: it has a well-developed, conical snout that gives the head a slightly concave profile from the snout tip back to the anterior nares, in contrast to the blunt-faced short-snouted corys. It reaches around 3 in in the male and about 3 in in the female, with the deep, armoured, helmet-headed body shape of the genus — two rows of overlapping bony plates down each flank, three pairs of barbels at the downturned mouth, and stiff leading spines in the dorsal, pectoral and adipose fins.
The colour pattern is diagnostic: two moderate-sized dark-brown to black blotches on the caudal-fin base, a longitudinal dark stripe along the midline of the rear flank, and — distinctively — no dark stripe crossing the eye. Internally it is set apart by features the describers detailed, including a temporal sensory-canal branch with two pores at the sphenotic, three series of teeth on the upper branchial tooth plate, and a small fleshy flap at the corner of the mouth below the maxillary barbel.
Habitat
The species is known from the rio Madeira basin in the Madre de Dios region of south-eastern Peru — type material came from a stream tributary of the río Manuripe in an area locally called 'Alegría,' with additional records from a tributary of the río Madre de Dios. These are Amazon-headwater streams of the western lowlands, draining toward the Madeira.
Long-snouted corys of this kind are typically fish of flowing clearwater streams over sand, where the elongate snout is used to probe more deeply into the substrate than the short-snouted species manage. Hobby husbandry data point to warm water around 72–79 °F across a broad pH band from mildly acidic to slightly alkaline (about 6.5–8.0); dedicated field measurements at the type locality are limited, so the aquarium ranges below are best treated as practical guidance.
Feeding
Corydoras fulleri is a benthic omnivore and detritivore that forages by sifting soft substrate, tasting out small invertebrates, insect larvae, worms and detritus with its barbels and expelling cleaned sand through the gills. The long, conical snout is a feeding adaptation, letting it dig and probe more deeply into sand than the blunt-faced corys — long-snouted species tend to work a slightly different microhabitat of the streambed. In the aquarium it accepts sinking foods, frozen bloodworm and brine shrimp, and small live foods.
Mating
Corydoras are egg-laying shoalers with no pair bond and the well-known T-position courtship. A ripe female cleans a spawning site; a male aligns himself at right angles to her head, and the female clasps a few eggs in a pelvic-fin basket and presses them onto the chosen surface, the sequence repeating a few eggs at a time. Behaviour specific to C. fulleri has not been described in the literature, but the long-snouted corys follow this same general reproductive pattern.
Breeding
Captive breeding of Corydoras fulleri has been achieved by specialist keepers — the original description and associated work even illustrate fry development — but it is not a routinely bred trade fish, and detailed published protocols are sparse. By analogy with related long-snouted corys, spawning is the familiar egg-scattering pattern: adhesive eggs laid in small batches on cleaned surfaces, often triggered by a cool water change mimicking seasonal rain, with no parental care, so eggs or parents must be separated. Fry hatch within a few days and take microworm and baby brine shrimp once the yolk is absorbed.
In the aquarium
Fuller's cory is a desirable but uncommon aquarium fish, of interest mainly to cory specialists. The standard genus husbandry applies and matters: keep it as a shoal of six or more, never singly or in pairs, over soft sand so the long snout and barbels are not damaged — substrate quality is especially important for a digging long-snouted species. Provide clean, well-oxygenated water with a gentle current, in keeping with its clearwater-stream origin, at a comfortable tropical temperature around 72–79 °F and a broad pH range. It is peaceful and suits a calm community of tetras, small characins and other gentle fish. As with all corys, use a cup rather than a net to avoid spine-tangling, and transport carefully, as a stressed fish can release skin toxins dangerous in the small volume of a bag.
Conservation
Corydoras fulleri has not been assessed by the IUCN, so its status is Not Evaluated. As a recently described species known from a limited area of the upper Madeira drainage in Peru, its true range and population size are not yet well established. Western-Amazon headwater streams face pressures from deforestation, agriculture, gold mining and associated pollution in the Madre de Dios region, which could affect localised species; without a formal assessment, the conservation status of this cory remains genuinely unknown.