Taxonomy & naming
Aspidoras raimundi was described by the Austrian ichthyologist Franz Steindachner in 1907 — the same year Rodolpho von Ihering established the genus Aspidoras for small corydoradine catfishes of the family Callichthyidae. Steindachner originally placed the fish in Corydoras; it was subsequently combined into Aspidoras, which is why the authority is cited in parentheses, '(Steindachner, 1907)'. The genus is set apart from Corydoras chiefly by its divided, double dorsal fontanel.
Aspidoras survived the 2024 revision of the Corydoradinae by Dias, Tencatt and colleagues as a recognised lineage genus; that study broke up the swollen genus Corydoras into several lineages (Brochis, Hoplisoma, Osteogaster, Gastrodermus and others) while leaving Aspidoras standing, so Aspidoras raimundi keeps its combination. The Catalog of Fishes (Eschmeyer, California Academy of Sciences) lists it as a valid species. The epithet raimundi is a patronym; the honouree was not stated by Steindachner, but Nijssen and Isbrücker (1976) suggested it commemorates a Brazilian associate of his named Raimundo.
Morphology
This is a small catfish, reaching about 1.5 in in standard length. It shows the standard corydoradine armour — two rows of overlapping bony scutes along each flank, a hard blunt head, three pairs of barbels framing the downturned mouth, and stiff leading spines in the dorsal and pectoral fins — on the slighter, narrower Aspidoras build.
The defining genus character is internal: the divided cranial fontanel that distinguishes Aspidoras from the single-fontanel Corydoras. In colour it is a pale, sandy fish marked with darker speckling and blotches, cryptic against the substrate of the clear north-eastern streams it inhabits. As with its congeners, the small body and subdued pattern make it an unobtrusive bottom-dweller.
Habitat
Aspidoras raimundi occurs in the rio Parnaíba basin of north-eastern Brazil — a large coastal drainage forming much of the border between the states of Piauí and Maranhão. It is a fish of streams and shallow margins, foraging over sand and fine substrate in the warm, soft waters characteristic of the region.
Reported conditions are cooler and more acidic than for many tropical corys: water temperatures around 68–73 °F and a pH of roughly 5.8–6.5, indicating the soft, slightly acidic stream water of the Parnaíba system. These figures match the clear-water, sandy-bottom habitats favoured by the genus, where the fish keeps low and sifts the bed for food.
Feeding
Aspidoras raimundi is a benthic micro-omnivore, foraging the way all corydoradines do — burying its barbels in sand and detritus to taste out small invertebrates, insect larvae, micro-crustaceans, worms and organic matter, then sifting substrate through the mouth and out the gills. Its small size confines it to small prey items. No specialised diet has been recorded; it is a generalist sand-sifter of the stream bed, and in captivity would take small sinking foods, micro-pellets and small frozen or live items.
Mating
Spawning has not been documented in detail for Aspidoras raimundi, but the genus follows the corydoradine pattern: egg-laying shoalers with no pair bond. Courtship reaches the characteristic 'T-position', with a male aligning at right angles to the female's head; the female carries a small clutch of eggs in a basket formed by her pelvic fins and presses the adhesive eggs onto a cleaned surface, repeating the act in small batches. A. raimundi is expected to follow this same well-established corydoradine sequence.
Breeding
There is no published captive-breeding account specific to Aspidoras raimundi, which is rarely seen in the trade. Drawing on the genus, it is an egg-scatterer that gives no parental care: adhesive eggs are laid in small batches on surfaces and then abandoned, with adults liable to predate them. The cooler, more acidic water reported from its range hints that, as with other Aspidoras, spawning may be cued by softer, cooler conditions mimicking seasonal rains. Fry would be tiny and require very small first foods, but the specifics remain inferred from relatives rather than recorded for this species.
In the aquarium
Aspidoras raimundi is an infrequent import seen mainly by specialist keepers. Its care follows that of small, soft-water corydoradines: keep a group of six or more over fine sand, in clean, well-oxygenated water with gentle current and regular changes. The temperature and pH reported from the wild — cooler, around 68–73 °F, and soft and slightly acidic — are a useful guide; this is not a fish for hard, warm water.
As a tiny, peaceful bottom-dweller it belongs in a calm community of small species that will not outcompete it at feeding time, on a soft sandy substrate that protects its barbels. The usual corydoradine precautions apply: avoid sharp gravel, handle with a cup rather than a net where possible because the fin spines tangle, and do not let it subsist on leftovers.
Conservation
Aspidoras raimundi is assessed by the IUCN Red List as Least Concern, evaluated in 2018. It is distributed through the substantial rio Parnaíba basin and faces no identified species-specific threats. The broader pressures on north-eastern Brazilian rivers — agriculture, water abstraction, damming and pollution within the Parnaíba drainage — degrade the shallow, sandy stream habitats it uses, but the species as a whole is currently regarded as secure.