Taxonomy & naming
Aspidoras psammatides was described in 2005 by Marcelo Britto, Flávio Lima and Adriana Santos, from the rio Paraguaçu basin in the Chapada Diamantina of Bahia. The genus Aspidoras was established by Rodolpho von Ihering in 1907 within the family Callichthyidae, for small corydoradine catfishes separated from Corydoras chiefly by the divided, double dorsal fontanel of the skull and the narrow frontal bones — features prominent in the diagnosis of this species, which has an 'extremely narrow frontal bone'.
The genus came through the 2024 revision of the Corydoradinae by Dias, Tencatt and colleagues intact: that study split the unwieldy genus Corydoras into several lineages (Brochis, Hoplisoma, Osteogaster, Gastrodermus and others) while recognising Aspidoras as a valid lineage genus in its own right. So Aspidoras psammatides keeps its original combination, and the Catalog of Fishes (Eschmeyer, California Academy of Sciences) lists it as a valid species. The whimsical epithet psammatides was coined from the Greek psammos, 'sand', the authors naming the fish after 'Psammatos psammatides, the sand sorcerer' — a nod to the sandy bottoms it inhabits.
Morphology
This is a small catfish, reaching about 1 in in standard length. It carries the corydoradine body plan — two rows of overlapping bony scutes down each flank, a hard blunt head, three pairs of barbels around the downturned mouth, and stiff spines at the front of the dorsal and pectoral fins — on the smaller, narrower Aspidoras frame.
The species was diagnosed on a suite of fine osteological characters, notably the extremely narrow frontal bone, together with its colour pattern: a series of dark marks along the body that give it the aquarium name 'dashed catfish'. As an Aspidoras it has the characteristic divided cranial fontanel that separates the genus from Corydoras. The overall effect is a pale, sand-toned fish patterned to disappear against the bright, sandy substrate of its native streams.
Habitat
Aspidoras psammatides is a narrow endemic, known only from tributaries of the upper rio Paraguaçu — a coastal river basin of eastern Brazil — in the Chapada Diamantina, Bahia. The type material came from affluents of the rio São José, one of the main tributaries of the upper Paraguaçu. This is upland habitat in a striking tableland landscape.
The published habitat description is unusually specific: the fish lives in highly transparent, brownish (tea-coloured) water up to about a metre deep, with moderate current, over a substrate of sand, gravel and larger rocks. The tea staining points to humic, soft, slightly acidic water typical of clear upland streams draining sandstone terrain. The restricted, single-basin distribution makes it one of the more geographically confined members of its genus.
Feeding
Like all corydoradines, Aspidoras psammatides is a benthic micro-omnivore that forages by sifting the substrate. It works the sand and gravel of its stream bed with its barbels, taking small invertebrates, insect larvae, micro-crustaceans, worms and organic detritus, and expelling cleaned grains through the gill openings. Its small size limits it to small prey. No specialised diet has been reported; its feeding ecology is that of a typical sand-sifting corydoradine of clear upland water.
Mating
Reproductive behaviour has not been documented in detail for this species, but Aspidoras follow the corydoradine pattern: egg-laying shoalers with no pair bond, spawning in the characteristic 'T-position' in which the male aligns at right angles to the female's head. The female holds a small clutch of eggs in a pelvic-fin basket and presses the adhesive eggs onto a cleaned surface, repeating the sequence in small batches. There is no reason to think A. psammatides departs from this well-established corydoradine courtship.
Breeding
No captive-breeding account specific to Aspidoras psammatides appears in the literature; the species is a recently described, narrowly distributed endemic rarely if ever seen in the trade. Inference from the genus suggests egg-scattering with no parental care, modest clutches of adhesive eggs deposited on surfaces and then abandoned, and tiny fry that would require very small first foods. As with many Aspidoras, cooler, softer water and a seasonal-rains cue are likely to be involved in triggering spawning, but for this particular species that remains untested rather than recorded.
In the aquarium
Aspidoras psammatides is essentially unknown in the aquarium trade — a localised Bahian endemic of interest mainly to specialists and ichthyologists rather than a commercial import. Were it kept, its care would follow that of small, soft-water corydoradines from clear upland streams: a group of six or more over fine sand, clean and well-oxygenated water, gentle current, and the soft, slightly acidic, tea-stained conditions of its home streams. As a tiny, peaceable bottom-dweller it would need calm, small tankmates and an undamaged sandy substrate to sift, with the usual corydoradine cautions around sharp gravel and netting. For now it is better appreciated as a wild species than as an aquarium subject.
Conservation
Aspidoras psammatides is assessed by the IUCN Red List as Least Concern, evaluated in 2018. That listing should be read against its very narrow range: the species is known only from the upper rio Paraguaçu in the Chapada Diamantina, so any localised pressure on those streams — water abstraction, agriculture, mining, sedimentation or pollution in the Bahian highlands — bears directly on the whole known population. A single-basin endemic of clear upland water is inherently more vulnerable to local habitat change than a widespread species, and continued monitoring of the Paraguaçu headwaters is the sensible safeguard.