Taxonomy & naming
Aspidoras depinnai was described by the Brazilian ichthyologist Marcelo Britto in 2000, in the journal Copeia, from a stream along the Amaraji–Primavera road in the rio Ipojuca basin of Pernambuco State. The species honours Britto's colleague Mário de Pinna. The genus Aspidoras Ihering, 1907 is a small group of exclusively Brazilian armoured catfishes (family Callichthyidae, subfamily Corydoradinae), close to Corydoras but set apart by skull anatomy, including the retention of two cranial fontanels.
The major 2024 revision of the Corydoradinae by Dias, Tencatt and colleagues (DOI 10.1093/zoolinnean/zlae053) broke the bloated genus Corydoras into several genera (Brochis, Hoplisoma, Gastrodermus, Osteogaster and others) but kept Aspidoras as a distinct, intact lineage — so the fish remains Aspidoras depinnai, and Catalog of Fishes (Eschmeyer, CAS) lists it as valid under that name. The genus revision by Tencatt and co-authors (2021) provided a full modern redescription of this species, one of the better-documented members of Aspidoras.
Morphology
Aspidoras depinnai is a small catfish reaching around 1.5 in in standard length, with the typical corydoradine build: a deep, armoured body sheathed in two rows of overlapping bony scutes, three pairs of barbels around a small downturned mouth, and stiff spines at the front of the dorsal and pectoral fins. As in all Aspidoras, the skull carries two fontanels.
Its most useful field mark is the dorsal fin: a conspicuous concentration of dark-brown to black pigment forms a large blotch across the middle of the fin, a feature shared with only a handful of congeners. The body ground colour is a light or brownish yellow with a dark-brown crown to the head, overlaid with variable darker markings along the flank. Internally, the species is diagnosed by details of its complex vertebra (with a moderately developed parapophysis) and of the first infraorbital bone, together with a distinctive irregular row of minute pores along the side of the snout that Britto noted in the original description.
Habitat
Aspidoras depinnai lives in small Atlantic-slope rivers of Pernambuco, in north-eastern Brazil. Its type locality is in the rio Ipojuca basin, and it has since been recorded from the rio Ipanema basin, a tributary of the lower rio São Francisco — so the species spans at least two adjacent drainages rather than a single stream. These are typical small corydoradine waters: shallow, flowing reaches over sand and leaf litter.
The genus, like Corydoras, includes facultative air-breathers able to gulp atmospheric oxygen, which helps such fish persist in the warm, sometimes low-oxygen streams of the region. Precise temperature, pH and hardness figures have not been published for this species, so the values used by keepers are inferred from the soft, warm waters of coastal north-eastern Brazil rather than measured directly for A. depinnai.
Feeding
Direct dietary studies of Aspidoras depinnai are lacking, but on the model of its genus and the wider Corydoradinae it is a benthic micro-omnivore. It works soft sediment and leaf litter with its sensory barbels, taking small invertebrates, insect larvae, microcrustaceans and organic detritus and expelling cleaned sand through the gill openings. In the aquarium, captive specimens accept the small sinking and frozen foods favoured by dwarf corydoradines.
Mating
Specific courtship observations for Aspidoras depinnai are not published, but the species is an egg-layer following the corydoradine pattern. Aspidoras and Corydoras are shoaling spawners without pair bonds: a ripe female cleans a surface, the group becomes active, a male pairs with her briefly in the characteristic close contact by which sperm reaches the eggs, and she then clasps a few adhesive eggs at a time in a basket formed by her pelvic fins and presses them onto the chosen site, repeating until the clutch is laid.
Breeding
Aspidoras depinnai has been bred by aquarists, and an alive aquarium specimen has been documented in the scientific literature, confirming its presence in cultivation. Detailed clutch sizes and developmental timings have not been formally published for the species, but small Aspidoras in general lay modest batches of adhesive eggs that the adults do not guard; the eggs hatch within a few days and the free-swimming fry take infusoria and then micro-foods such as baby brine shrimp and powdered diets. As with its relatives, a cool water change can help trigger spawning, and eggs or parents are usually separated to prevent predation.
In the aquarium
Among the north-eastern Brazilian Aspidoras, A. depinnai is one of the more likely to be encountered in the hobby, appearing in the trade from time to time as a small, lively dwarf cory. It calls for the same care as its kin: keep it in a shoal of six or more, because these are sociable fish that are stressed and inactive when kept alone or in pairs. Provide a soft sand substrate — coarse or sharp gravel abrades and infects the barbels, a common avoidable injury in corydoradines — together with gentle, well-oxygenated flow, clean water and regular changes. Warm but not hot temperatures in the low-to-mid 20s Celsius suit it, and it is utterly peaceful, best matched with small, calm tankmates such as tetras and other dwarf community fish. As a small armoured catfish it appreciates leaf litter and shaded cover, and its fin spines can snag in a net, so a cup is the safer way to move it.
Conservation
Aspidoras depinnai is assessed by the IUCN Red List as Least Concern (2018). Although its range is fairly restricted, the species is now known from more than one drainage in Pernambuco, recent surveys suggest it may occur in further tributaries of the area, and no specific threat to it is currently identified — the basis on which both the IUCN and the 2021 generic revision reached a Least Concern conclusion. That said, the small Atlantic-slope rivers of north-eastern Brazil are under broad pressure from deforestation, agriculture, urban growth and water abstraction, so continued monitoring of this regional endemic remains sensible.