Taxonomy & naming
Centromochlus schultzi was described by the German ichthyologist Hermann Rössel in 1962. It belongs to the family Auchenipteridae, the driftwood catfishes, within the subfamily Centromochlinae, and to the genus Centromochlus, a group of small South American catfishes often traded and kept for their compact size and internal-fertilisation biology.
The species has had an unsettled taxonomic history typical of Siluriformes: aquarium and trade literature has at times listed it under the genus Balroglanis before it was returned to Centromochlus, and hobbyist sources still occasionally use the older combination. The Catalog of Fishes (Eschmeyer, California Academy of Sciences) governs the valid name, and this article follows Centromochlus schultzi throughout.
Morphology
Centromochlus schultzi is a small, slender driftwood catfish reaching a documented maximum of about 4.5 in standard length (FishBase), with most aquarium specimens closer to 3.5–4 in. Like other members of its family it has a mottled, cryptic pattern of browns and tans that helps it blend into driftwood, leaf litter and root tangles, along with the flattened head, forward-set eyes and long, sensitive maxillary barbels typical of nocturnal benthic catfishes.
As in virtually all catfishes the skin is scaleless (naked), which makes it more sensitive to copper and many medications than scaled fish - dose conservatively, often at half strength, if treatment is ever needed. It carries the stiff, serrated, locking pectoral and dorsal spines typical of catfishes generally; while not dangerously venomous, these spines readily snag in aquarium nets, so the fish is best moved in a container rather than netted.
Habitat
The species is native to the upper Xingu and Tocantins river basins in Brazil, part of the southern Amazon drainage. Wild populations occupy river-margin habitats with driftwood, submerged roots and leaf litter, where the mottled body pattern provides effective camouflage against predators during the day.
Water in these basins is generally soft to moderately hard and close to neutral; hobbyist reports converge on a pH around 6.5-7.5 and a moderate temperature range of roughly 72–82 °F, which is consistent with a warm, well-oxygenated South American river rather than extreme blackwater conditions. It is best kept in dim, sheltered aquascapes that echo this driftwood-and-leaf-litter habitat.
Feeding
Centromochlus schultzi is a nocturnal benthic omnivore and opportunistic micro-predator. In the wild it forages after dark over submerged wood and leaf litter for small invertebrates such as ants, beetles and mayflies, along with other aquatic insects and detritus.
In the aquarium it readily accepts sinking catfish tablets and pellets, frozen bloodworm and daphnia, and other small prepared or live/frozen foods. Because it feeds primarily at night, it does best when offered food after the lights go out, so it is not out-competed by more active daytime tankmates; targeted after-dark feeding also lets keepers confirm the fish is thriving even though it is rarely seen foraging by day.
Mating
Centromochlus schultzi shares the unusual reproductive biology of its family: driftwood catfishes (Auchenipteridae) use internal fertilisation rather than the external egg-scattering typical of most catfishes. The male's anal fin is modified into an intromittent organ used to transfer sperm directly to the female during a brief mating event.
What makes this species particularly notable is that the female then stores the sperm internally and can lay a fertile clutch weeks later, without the male present at spawning. The first reported captive spawning documented a roughly 3.5-4 inch (about 3.5–4 in) female laying more than 200 eggs bound together in a gelatinous mass, deposited under stones or bogwood - a reproductive strategy genuinely rare among catfishes and worth stating explicitly to aquarists expecting a conventional egg-scatter.
Breeding
Following mating and internal fertilisation, the female Centromochlus schultzi deposits her fertilised eggs - bound in a gelatinous mass - under a stone, piece of bogwood or similar sheltered surface, often with no male in attendance at the time of laying. Documented spawns have produced clutches of 200 or more eggs from a single female.
Parental care beyond egg placement appears minimal or undocumented in the available literature; keepers hoping to breed this species should provide plenty of driftwood, rockwork and cave-like hiding spots as potential egg-laying sites, condition a group on a varied diet, and expect the female's ability to store sperm to make the timing of any given spawn hard to predict. This is one of the few auchenipterids with a documented aquarium spawning report, though captive breeding remains occasional rather than routine.
In the aquarium
At a modest adult size of about 4.5 in standard length, Centromochlus schultzi is a manageable aquarium catfish, though its real adult size should still be planned for rather than assumed away - a mature specimen is not a permanently tiny fish. A tank in the region of 20–25 US gal upward, furnished with driftwood, roots and dim lighting, suits its nocturnal, cover-seeking habits well; it is a social species best kept in a group of five or six rather than alone.
As a scaleless catfish it is more sensitive than scaled fish to copper-based medications and should be dosed conservatively. Its locking pectoral and dorsal spines can snag in a net, so scoop it with a container instead. It is peaceful and well suited to a South American community of tetras, small barbs, dwarf cichlids and corydoras, and being nocturnal it appreciates feeding after lights-out so it can forage without competition from more active daytime fish.
Conservation
The IUCN Red List assesses Centromochlus schultzi as Least Concern. It occupies a defined range within the upper Xingu and Tocantins basins of Brazil and is not currently considered at elevated risk of extinction.
As with many South American driftwood catfishes, the wider conservation picture for its home rivers - the Xingu basin in particular has faced substantial hydroelectric development and habitat pressure - is worth watching even where the species-level assessment remains favourable. The aquarium trade for this species is limited, and specific data on collection pressure or captive-breeding supply is sparse.