Taxonomy & naming
Akysis microps was described by Heok Hee Ng and Heok Hui Tan in 1999. It belongs to the family Akysidae, the stream catfishes or Asian stone catfishes, a family of small, benthic, hillstream-adapted catfishes distributed across South and Southeast Asia. The genus Akysis is one of the largest in the family, with dozens of described species, many of them narrow-range stream endemics distinguished by fine details of barbel length, fin-spine serration and colour pattern.
The Catalog of Fishes treats Akysis microps as the valid name for this species; there is no evidence in the available sources of it ever circulating under an older combination. The genus name Akysis is a coined taxonomic name without an obvious classical root; the specific epithet microps is built from Greek mikros (small) and ops (eye, face), referring to the species' notably small eyes — a useful field character among the many similar-looking small Akysis species.
Morphology
Akysis microps is a genuinely tiny catfish, reaching only about 1 in standard length (1 in in measured specimens) — smaller than many aquarium fish keepers would even recognise as an adult catfish. Like all akysids it has a flattened head, a slim, tapering body and a naked, scaleless skin rather than the bony armour plating seen in some other catfish families, which makes it sensitive to certain medications (see "In the aquarium").
The species carries the family's characteristic barbels around the mouth for tactile foraging over the streambed, and — as its name suggests — comparatively small eyes. At the base of the dorsal and pectoral fins it bears a venom apparatus associated with the spines, capable of delivering a painful sting if the fish is handled carelessly; these spines also lock rigid and can snag in aquarium nets.
Habitat
The species is known from the Endau River drainage in Malaysia, its type locality, where it inhabits large streams with sandy bottoms at moderate depth (around 19.5 in). This is fast-flowing, well-oxygenated, clear tropical stream water typical of Southeast Asian hillstream systems rather than a still, sluggish or blackwater habitat.
Data on the finer water chemistry of its home streams is sparse in the sources available; hobbyist care sheets recommend replicating strong current — on the order of 4 to 5 times tank volume per hour — to match this flowing habitat, over a sandy substrate the fish can bury into or forage across.
Feeding
Akysis microps is a nocturnal micropredator, foraging over the streambed mostly after dark for small invertebrates. In the aquarium it does best on small live or frozen fare — Artemia (brine shrimp), Daphnia, bloodworm and glassworm are all taken readily — and newly imported fish may initially refuse dried or prepared foods, so live and frozen items are the safer starting point.
As with most nocturnal catfish, feeding is best timed after lights-out, both to match the species' natural rhythm and to reduce competition from more visible, active tankmates during the day.
Mating
No courtship or spawning behaviour has been documented for this species in the available sources. Data is sparse for Akysis microps specifically, and detailed breeding accounts are scarce across the genus generally; nothing here should be assumed by analogy to other, better-studied catfish families.
Breeding
Breeding of Akysis microps has not been documented in the aquarium according to the sources available, and no aquaculture or hobbyist spawning reports were found. As with many small stream-dwelling Akysidae, this is a species that arrives via wild collection rather than captive breeding programmes; prospective keepers should not expect to breed it and should treat any offered stock as wild-caught.
In the aquarium
Because Akysis microps tops out around 1 in SL, tank size demands are modest by catfish standards — a base of around 45 x 12 in is reported as sufficient for a small group — but strong water flow (roughly 4–5 times tank volume per hour) is important to replicate its fast-flowing stream habitat, along with a sandy substrate and good oxygenation. It is reported as non-aggressive toward its own kind and can be kept singly or in a group.
Two care points follow directly from its biology. First, like other akysids it is scaleless and naked-skinned, making it more sensitive than scaled fish to copper and many medications — a conservative, often half-strength dose is advised when treatment is unavoidable. Second, it carries venomous, locking spines at the base of the dorsal and pectoral fins that can deliver a painful sting and readily snag in a net, so it is best scooped and moved in a container rather than netted directly. As a nocturnal micropredator it should be offered cover during the day and fed after lights-out.
Conservation
The IUCN Red List assesses Akysis microps as Data Deficient, with an assessment dated 2018–2019. As a narrow-range stream endemic known from the Endau River drainage of Malaysia, its population trend and the pressures it faces — such as habitat alteration, sedimentation or water extraction affecting Southeast Asian hillstream systems generally — have not been comprehensively evaluated, and no numeric IUCN assessment identifier was available in the sources consulted.