Taxonomy & naming
Microglanis berbixae was described in 2020 by Tobes, Falconí-López, Valdiviezo-Rivera and Provenzano in the journal Neotropical Ichthyology, based on material collected from Quebrada Sune, a tributary of the Pachijal River in Pichincha Province, Ecuador. It belongs to the family Pseudopimelodidae — the bumblebee catfishes and their relatives, a group of small, big-headed, scaleless catfishes long lumped with the pimelodids before being split out as its own family.
The species is notable as only the second species of Microglanis documented from the trans-Andean (Pacific slope) region, the genus otherwise being centred on the Amazon, Orinoco and other cis-Andean drainages of South America. The genus name Microglanis is Greek for "small catfish"; the species epithet berbixae honours María Resurección Sesma Lizari, known as "Berbixe," the mother of the paper's first author. The Catalog of Fishes treats Microglanis berbixae as the current valid name; it has not been placed in any other genus.
Morphology
Microglanis berbixae is a genuinely small catfish: the holotype male measured 2 in standard length (about 2 in), and the type series ranged from 1.5–2 in SL. Like all pseudopimelodids it has a broad, flattened head relative to its body, a wide mouth fringed with barbels, and completely scaleless, naked skin.
Coloration is understated — a uniform pale brown, yellowish or grayish body without the bold spots, bars or blotches seen in some relatives — but the species is marked by a distinctive dark, crescent-shaped (lunate) band across the base of the caudal fin, a feature used to separate it from other Microglanis. As with other members of the genus, expect small, stiff spines at the leading edge of the dorsal and pectoral fins; move the fish in a net-free container rather than a mesh net to avoid snagging.
Habitat
The species is known only from the Pacific slope of Ecuador, in the Esmeraldas River basin — specifically Quebrada Sune, a small tributary of the Pachijal River in Pichincha Province. This is trans-Andean drainage, distinct from the Amazon-basin streams that most Microglanis species call home.
FishBase describes the habitat as the central area or mouth of a stream with shallow rapids, over a mixed substrate of pebbles, small boulders, sand, gravel and bedrock — a moderate-flow, rocky-bottomed small-stream environment typical of foothill drainages. Specific water chemistry (temperature, pH) was not recorded in the original description or on FishBase; care parameters below are drawn from the wider genus rather than measurements at this exact site, so treat them as a starting point rather than site-verified data.
Feeding
No feeding data specific to Microglanis berbixae has been published; what follows is inferred from the genus. Bumblebee-group Microglanis are nocturnal benthic micro-predators and omnivores, foraging along the stream bottom after dark for small invertebrates and detritus rather than actively hunting in open water during the day.
In the aquarium, genus husbandry notes call for small meaty foods — bloodworm, mosquito larvae, brine shrimp, daphnia — plus sinking catfish pellets, with live blackworms taken readily when available. Because the fish is nocturnal, offering food after the lights go out helps ensure it actually gets fed rather than being outcompeted by diurnal tankmates.
Mating
No courtship or spawning behavior has been documented for Microglanis berbixae in the wild or in the aquarium. Data is sparse to the point of absence: the original description is a taxonomic account based on preserved museum material, not a field or captive-breeding study, so nothing is known about how this species finds mates or times its spawning.
Breeding
Breeding in Microglanis berbixae is undocumented — there are no published reports of this species being bred in captivity, and no field observations of its reproductive behavior. Genus-level notes for Microglanis describe minimal broodcare and eggs simply deposited among plants or cover rather than any elaborate nest-building or guarding, but this has not been confirmed for berbixae specifically, so it should not be presented as established fact for this species. Anyone keeping this fish is working essentially without a breeding roadmap.
In the aquarium
Microglanis berbixae stays small — the known size range tops out around 2 in SL — so a modestly sized aquarium can comfortably house it, but it is still a scaleless catfish and should be treated with the same caution as any naked-skinned species: dose copper-based and other medications conservatively, often at half strength, and monitor closely. Keep the water clean with regular partial water changes, since scaleless catfish tend to be more sensitive to nitrogenous waste buildup than scaled fish.
Expect a nocturnal, bottom-dwelling fish that wants rock, gravel and cover to hide in during the day, echoing the rapids-and-rubble stream habitat it comes from. Provide moderate flow and a well-oxygenated setup rather than still water. As with other small catfishes, handle it in a container instead of a net — the dorsal and pectoral spines can snag mesh and jab a careless hand. Because this species is known from a single small Ecuadorian stream and has essentially no aquarium track record, treat any specimen in the trade as wild-collected and be conservative about its needs until more is documented.
Conservation
Microglanis berbixae has not yet been evaluated by the IUCN Red List and carries a status of Not Evaluated. Given that it is known only from a single small tributary stream — Quebrada Sune, on the Pacific slope of Ecuador — its true range and population status are essentially unassessed, and a species this narrowly distributed can be vulnerable to local habitat disturbance, deforestation or water-quality changes even without a formal conservation listing.
As with many recently described, single-locality Neotropical catfishes, there is no meaningful aquarium trade documented for this species; it should not be assumed to be an established or sustainably sourced ornamental fish.