Taxonomy & naming
Microglanis leniceae was described by Oswaldo T. Oyakawa (working under Shibatta, 2016) from the rio Betione, a tributary of the upper rio Paraguay basin in Mato Grosso do Sul, Brazil. It belongs to the family Pseudopimelodidae — the bumblebee catfishes — a group of small, wide-mouthed, big-eyed South American catfishes long confused with Pimelodidae before being split out as its own family. The genus Microglanis is the largest in the family, with species scattered across the Amazon, Orinoco, Paraguay and coastal river systems of South America; many, like this one, are described from single river drainages and remain poorly known outside their type description.
The genus name Microglanis combines Greek mikros ("small") with glanis (an old name for a catfish), a fitting label for a genus in which every species stays under about 3 in SL. The species epithet leniceae honours Lenice Souza-Shibatta, an ichthyologist and the wife of the describing author, a common convention in taxonomic naming. No historical synonyms or older combinations are documented for this species — it has carried the name Microglanis leniceae since its 2016 description.
Morphology
Microglanis leniceae is diminutive even by the standards of its genus: the type series ranges from 1–1.5 in standard length, with the holotype measuring 1.5 in SL — call it about 1.5 in as a practical adult maximum. Like other Microglanis it has the classic bumblebee-catfish silhouette: a broad, flattened head, a wide terminal mouth fringed with barbels, small eyes, and a deeply forked caudal fin that sets it apart from many other pseudopimelodids.
The skin is naked and scaleless, as in all catfishes, which has direct consequences for how it should be medicated (see "In the aquarium"). As in related Microglanis, the pectoral-fin spine shows size-dependent development of hooking or serration, becoming more pronounced as the fish matures — a small but genuine locking spine that can snag a soft aquarium net. Detailed colour pattern was not itemised in the cache notes here, but congeners in the genus typically show the bold, high-contrast banding that gives the group its "bumblebee" nickname.
Habitat
The species is known from the rio Betione, rio das Pitas and rio Cuiabá, tributaries within the upper rio Paraguay basin in the states of Mato Grosso and Mato Grosso do Sul, Brazil — part of the Paraguay freshwater ecoregion of central South America. This places it in warm tropical lowland rivers typical of the Pantanal-draining headwaters, though the original description does not report specific water chemistry (temperature, pH or hardness) for the type locality, and no further habitat study has been located.
Given the genus and family, it almost certainly lives as a nocturnal, benthic micro-predator among leaf litter, submerged wood and marginal vegetation rather than in open water — but until more field data is published, treat the fine habitat details as data sparse rather than firmly established.
Feeding
No dedicated dietary study exists for Microglanis leniceae, but its family and genus give a reliable picture: pseudopimelodids are nocturnal benthic micro-predators and opportunists, ambushing small invertebrates, insect larvae and other tiny prey from cover after dark. The wide mouth and forward-set eyes typical of the genus are built for this ambush strategy rather than for grazing.
In the aquarium, Microglanis species take standard sinking foods without fuss — small pellets, frozen bloodworm and brine shrimp, and other prepared foods — provided the food reaches the bottom where the fish forages. Because it is most active after dark, feeding once room lights are out helps ensure a shy, nocturnal fish this small is not out-competed by faster tankmates.
Mating
No courtship or spawning behaviour has been documented for Microglanis leniceae in the wild or in captivity. Data on reproduction in the genus Microglanis generally is thin; most species are known only from museum material collected outside any breeding context, so specifics of pairing, courtship displays or spawning triggers are not established for this species and should not be assumed from other catfish groups.
Breeding
Breeding of Microglanis leniceae has not been documented, either in the wild or in the aquarium, and no captive-breeding reports for this species are known. More broadly, small pseudopimelodids in this genus are rarely if ever bred by hobbyists; general accounts for Microglanis note that where breeding of related species has been attempted, softer, slightly acidic water is suggested as a spawning cue, but this remains generic genus-level guidance rather than a confirmed protocol for this species. Any fish in the trade should be assumed wild-collected rather than captive-bred, and parental care, egg placement and fry development are simply unrecorded — this is honestly an open question rather than a settled one.
In the aquarium
Microglanis leniceae is genuinely tiny — adults max out around 1.5 in — so unlike many catfish in this atlas there is no size trap here; a small, well-aquascaped nano tank suits it far better than a large show tank. That said, its small size cuts both ways: it is easily out-competed for food by larger or faster tankmates and can even be at risk from fish that would otherwise be considered peaceful, so tankmates should be chosen with real care.
As with all catfish, the skin is scaleless, so this species is more sensitive than scaled fish to copper-based medications and should be dosed conservatively if treatment is ever needed. The pectoral spine can lock and, though small, is stiff enough to catch in netting — scooping the fish into a container rather than chasing it with a net avoids stress and injury to both fish and keeper. Being nocturnal, it appreciates driftwood, leaf litter and other cover to retreat into by day, becoming more visible as the tank lights dim. Given the sparse water-chemistry data from its native rivers, aim for stable, warm tropical conditions and avoid extremes rather than trying to replicate an undocumented ideal.
Conservation
The IUCN Red List currently lists Microglanis leniceae as Least Concern, reflecting its occurrence across a reasonably wide swath of the upper rio Paraguay basin without documented major habitat fragmentation or population decline. As with many recently described, narrow-range Neotropical catfishes, this assessment rests on limited survey effort rather than intensive population monitoring, so the picture could change as more data accumulates.
The upper Paraguay basin, part of the Pantanal wetland system, faces ongoing pressures from agricultural expansion, deforestation and water-management schemes, so even a currently secure species like this one is tied to the health of a specific set of tributaries rather than a vast, resilient range.