Taxonomy & naming
Microglanis minutus was described in 2010 by Ottoni, Mattos & Barbosa in the journal Vertebrate Zoology, based on a holotype (UFRJ 7742) measuring just 1 in standard length. It belongs to the family Pseudopimelodidae — the bumblebee and dwarf pimelodid catfishes — and is placed within the M. parahybae species group inside the genus Microglanis. The Catalog of Fishes treats Microglanis minutus as the current valid name; there is no older combination to correct, since the species was named directly into Microglanis and has not been shuffled between genera.
The genus name Microglanis is Greek, from mikros ("small") and glanis (an old name for a catfish), a fitting label for a genus of diminutive pseudopimelodids. The species epithet minutus is Latin for "small" or "tiny", chosen by the describing authors specifically because this species is smaller than its closest relatives in the parahybae group — a name that doubles as a care warning: this is not a fish that grows into anything substantial.
Morphology
Microglanis minutus is described from specimens around 1 in (about 1 in) standard length, making it one of the smallest catfishes in the genus. The original description notes mottled, faintly banded pectoral and anal fins, a series of dark brown saddle-shaped blotches along the trunk, and a pale oval spot beneath the base of the dorsal spine — a cryptic, broken pattern typical of small benthic pseudopimelodids. The caudal fin is emarginate (shallowly notched) rather than deeply forked.
A distinguishing feature singled out in the description is a distinct bony point at the tip of the pectoral spine, used alongside other spine and fin-ray characters to separate M. minutus from its closest congeners. Like other Pseudopimelodidae, the body is scaleless (naked-skinned) rather than armour-plated, which has direct implications for medicating this fish (see "In the aquarium"). The species carries the stiff, serrated pectoral spines typical of the family, which can lock in an extended position.
Habitat
The species is known only from the Rio Barra Seca basin in Espírito Santo state, southeastern Brazil — a small coastal river drainage, not one of the major Amazon or Paraná systems. FishBase records it as a tropical freshwater, demersal (bottom-dwelling) fish, consistent with its pseudopimelodid relatives, which typically shelter among leaf litter, roots, and submerged debris on the streambed by day.
Because the species was described only in 2010 and has attracted very little subsequent study, no published temperature or pH readings for its native water are available. Given the coastal Atlantic Forest drainages of Espírito Santo, warm, soft, mildly acidic stream conditions are typical of the region, but this is inference from the surrounding basin rather than a measured figure for the Rio Barra Seca itself — treat any specific water chemistry as provisional until better data exists.
Feeding
No dedicated dietary study of Microglanis minutus has been published. Related Microglanis species and other small Pseudopimelodidae are nocturnal benthic omnivores/micro-predators, foraging over the substrate after dark for aquatic invertebrates, detritus and small prey items — a pattern PlanetCatfish notes for other members of the genus, which take fresh and frozen foods readily in captivity.
In the absence of species-specific data, the safest working assumption is the genus-typical pattern: offer sinking foods after lights-out rather than assuming this fish will compete for food during the day. Frozen bloodworm, brine shrimp, and small sinking pellets fit what is known of the genus, though this extrapolation should be treated as a starting point, not a confirmed fact for M. minutus itself.
Mating
No courtship or spawning behaviour has been documented for Microglanis minutus in the wild or in captivity. The species was described from a small type series collected for taxonomic purposes, not from long-term field or aquarium observation, so there is no record of pairing behaviour, spawning triggers, or sexual dimorphism beyond what can be inferred from body shape in the original description — and even that was not the focus of the paper.
Given how little is published even for better-known Microglanis, nothing reliable can be said here beyond noting the gap. This is a case where honesty about missing data matters more than filling the section with borrowed generalities from unrelated catfish groups.
Breeding
There is no confirmed record of Microglanis minutus being bred in home aquaria, and the species does not appear to be established in the hobby at all — it was described only in 2010 from a restricted coastal Brazilian drainage and has essentially no aquarium-trade profile. Breeding data is simply unknown rather than negative: it has not been reported as achieved, and it has not been reported as attempted and failed.
As with many small, recently described Pseudopimelodidae, any responsible statement here has to stop at "not documented." There is no basis in the available sources for assigning a specific breeding mode (bubble-nest, cave-spawning, egg-scattering or otherwise), and doing so would be guesswork rather than fact.
In the aquarium
Microglanis minutus is barely represented in aquarium literature, so care information here is necessarily thin and drawn mostly from its family and genus rather than from direct accounts of the species. At roughly 1 in standard length it is a genuinely small catfish — unlike many of the larger long-whiskered cats in this atlas, the size trap runs the other way here: this is not a fish that will outgrow a modest aquarium, but its tiny size means it needs fine substrate, gentle tankmates, and food small enough to take.
Two care points carry over from its family regardless of how little else is known. First, like other Pseudopimelodidae it is scaleless (naked-skinned), so it should be treated as medication-sensitive — dose copper-based treatments and many standard medications conservatively, as with loaches, puffers and other scaleless catfish. Second, it carries stiff, lockable pectoral spines typical of the family; these can snag in a net, so move the fish in a container rather than netting it. Being nocturnal and benthic by family habit, it likely appreciates cover such as leaf litter or fine root tangles and is probably most active after dark, though this specific behaviour has not been directly documented for M. minutus.
Conservation
The IUCN Red List assesses Microglanis minutus as Least Concern, in an assessment dated 2018. This is a somewhat unusual result for a species restricted to a single small coastal river basin (the Rio Barra Seca) in a heavily developed part of Brazil, and it should be read as reflecting the available evidence at the time of assessment rather than a guarantee of long-term security.
Espírito Santo's coastal Atlantic Forest drainages are under general pressure from agriculture, deforestation, and urban development, pressures that apply broadly to small-range endemics in the region even where a formal threatened listing has not (yet) been applied. As a narrow-range, recently described species with limited follow-up study, its status is worth revisiting as more survey data accumulates.