Taxonomy & naming
Chiloglanis neumanni was described by the Belgian-British ichthyologist George Albert Boulenger in 1911. It belongs to Mochokidae, the African squeakers and upside-down catfishes, and to Chiloglanis, a genus of small, flattened, rock-clinging suckermouth squeakers found across much of sub-Saharan Africa — a very different lifestyle from the free-swimming, whiskered Synodontis in the same family.
The taxonomy of this species is genuinely unsettled. Type material and the strict application of the name point to a narrow endemic of the Bubu River system in Tanzania. However, the fish widely sold in the aquarium trade as "C. neumanni" — usually collected alongside Lake Malawi mbuna exports — is now understood by specialists (see PlanetCatfish) to represent one or more undescribed species rather than the true Bubu River fish. Records citing C. neumanni across the Zambezi, Okavango, Kafue, Limpopo, Cunene and Lake Malawi/Kariba systems should therefore be treated with caution: some or most may belong to other, still-undescribed Chiloglanis. Buyers should not assume a fish labelled "neumanni" in a shop is the true species.
Morphology
Like other Chiloglanis, this is a small, dorsoventrally flattened catfish built for clinging to rock in current. The mouth is modified into a ventral, sucker-like oral disc fringed with papillae — quite unlike the barbel-fringed mouth of Synodontis — which the fish uses to grip smooth or rough stone surfaces in fast water while it grazes.
Maximum recorded size is only about 2.5 in standard length, making it one of the smallest catfish in the family. The skin, as in all mochokids, is completely scaleless (naked), which matters for medication dosing (see "In the aquarium"). It carries the stiff, serrated, locking pectoral and dorsal spines typical of squeakers, though at this small size they are correspondingly modest. No clear external sexual dimorphism has been documented for the species.
Habitat
True Chiloglanis neumanni is known from the Bubu River in Tanzania; fish passing under this name in the wider literature and trade are reported from a broad swath of southern and eastern African drainages including the Zambezi (above and below Victoria Falls), Okavango, Kafue, Limpopo, Cunene, Lake Malawi and Lake Kariba, though as noted above much of this range likely belongs to undescribed relatives rather than the true species.
Wherever it occurs, the habitat is consistent: shallow, well-oxygenated rocky riffles and rapids in cool, flowing streams, typically in water less than 8–12 in deep. Water is reported around pH 6.0–7.5 and 68–79 °F — moderately soft to slightly hard, neutral-ish water, not the strongly alkaline rift-lake chemistry associated with many Malawi cichlids it is sometimes exported alongside. Fish are benthopelagic, holding station against the current on stone surfaces rather than swimming freely in open water.
Feeding
Chiloglanis neumanni is an aufwuchs grazer — it scrapes the biofilm of algae, diatoms and associated microfauna off rock surfaces with its sucker mouth, supplementing this with small invertebrates picked from the same surfaces. This places it in the nocturnal benthic omnivore/micro-predator mould typical of small mochokids, foraging over the bottom mostly after dark.
In the aquarium it needs a tank with an established biofilm on rockwork and driftwood to graze continuously, plus sinking foods such as algae wafers, blanched vegetables and small frozen or prepared foods offered after lights-out so it is not out-competed by more active tankmates. It does not thrive as a pure algae-eater in a bare or newly set-up tank.
Mating
Little to nothing has been documented about courtship or spawning behaviour in Chiloglanis neumanni. Rock-clinging Chiloglanis in general are presumed to spawn in crevices or under stones in the fast water they inhabit, but no detailed account of pairing, courtship displays or egg-laying has been published for this species specifically. Sexes cannot reliably be distinguished externally.
Breeding
Breeding of Chiloglanis neumanni in captivity is rarely, if ever, achieved and is poorly documented — hobbyists report that simply keeping the species alive for several years is considered a notable success, let alone spawning it. No reliable account of a home aquarium spawning exists in the sources available. Given the genus's rock-crevice habits, a cave or cavity-spawning mode is plausible, but this should be treated as an educated guess rather than a confirmed fact, and there is no evidence of parental care being observed. Prospective keepers should not expect to breed this species and should treat any wild-collected or trade stock as effectively unbreedable in the home aquarium at present.
In the aquarium
This is a genuinely small catfish — adults top out around 2.5 in SL — but it is a demanding one, not a casual addition. It needs strong water flow, high oxygenation and an aquarium with mature, established biofilm on rocks and wood to graze continuously; it will not do well in a sterile or newly cycled tank. Aim for the cooler end of the tropical range, roughly 68–79 °F, and moderate pH (around 6.0–7.5) rather than the hard alkaline water of a Malawi mbuna tank it is sometimes sold alongside.
As with all mochokids the skin is scaleless, so it is more sensitive than scaled fish to copper-based and some other medications — dose conservatively. It also carries locking pectoral and dorsal spines that can snag in a net, so it is best scooped in a container rather than netted. Before buying, be aware that most trade specimens sold as "C. neumanni" (particularly those exported with Lake Malawi cichlids) are now thought to be undescribed look-alike species rather than the true, Bubu River-restricted C. neumanni — an honest label is hard to guarantee, and the species is not one to buy expecting to breed.
Conservation
Chiloglanis neumanni has not been evaluated by the IUCN Red List, so it carries no formal conservation status. The lack of assessment reflects both the small size and low profile of the species and the taxonomic confusion around it — a name applied to a rare Tanzanian river endemic on one hand and a widely traded but likely undescribed Malawi-region fish on the other makes it difficult to assess either population properly.
Because the true species appears restricted to the Bubu River system in Tanzania, any localized habitat pressure there — siltation, water abstraction or pollution — could disproportionately affect it given the apparently narrow range, though no dedicated population study is available to confirm current status. The wider trade in similar-looking Chiloglanis relies on wild collection alongside Lake Malawi cichlid exports.