Taxonomy & naming
Akysis clinatus was described by Heok Hee Ng and Walter J. Rainboth in 2005, based on a holotype and paratype series collected from the Stung Chhay River in southwestern Cambodia. It belongs to the family Akysidae — the stream catfishes — within the genus Akysis, a large assemblage of small, scaleless catfishes distributed across South and Southeast Asian hillstreams. The Catalog of Fishes treats Akysis clinatus as a valid species.
The genus name Akysis is a coined name with no direct classical translation, long used for this group of small Asian stream catfishes; the species epithet clinatus derives from Latin and was chosen by the describing authors to reflect a distinguishing morphological feature noted in the original description. As with many small, recently described akysids, the species has not been revisited in the taxonomic literature since its description, and no synonyms or historical combinations are documented — it has always been placed in Akysis.
Morphology
Akysis clinatus is a true miniature: the holotype (ZRC 47288) measured 1 in standard length, with paratypes ranging from 1–1.5 in SL. Species in the genus Akysis top out under about 3 in SL even at their largest, and clinatus sits at the small end of that range — this is a catfish that fits comfortably in a fingertip for its entire life, never a juvenile phase of something larger.
Like other akysids it has the typical stream-catfish build: a flattened head adapted for holding position in current, barbels around the mouth for feeling out food on the substrate, and — critically for care — completely scaleless, naked skin. That bare skin is a defining trait of the family and matters directly for keeping any akysid: scaleless catfishes are markedly more sensitive to copper and many common medications than scaled fish, and dosing should always be conservative. Fine details of fin-spine counts and body proportions distinguish clinatus from its congeners, but published descriptions of colour pattern and finer anatomy beyond the type description are not available in the sources consulted for this profile.
Habitat
The species is known only from its type locality, the Stung Chhay River near Tok Kong village in southwestern Cambodia, part of a small basin draining toward the Gulf of Thailand. This places it among a cluster of narrow-range Cambodian and Southeast Asian hillstream endemics rather than in the well-studied Mekong mainstem.
Akysid catfishes as a group are creatures of clear, fast-flowing streamlets, typically over sand, gravel or rock substrate, and members of the genus Akysis are generally kept and described in the literature as preferring cooler, well-oxygenated running water rather than still or warm lowland habitats. No dedicated ecological survey of Akysis clinatus itself has been published, so details of its specific microhabitat, seasonal behaviour and population status in the wild remain data sparse.
Feeding
Akysis clinatus has not been the subject of a dedicated dietary study, but its biology can be inferred confidently from its family and genus: akysid catfishes are nocturnal benthic micro-predators, foraging over the streambed after dark for small aquatic invertebrates such as crustaceans, worms and insect larvae. Its tiny adult size limits it to correspondingly tiny prey.
In aquarium care of the genus more broadly, Akysis species are reported as picky feeders that generally refuse dried foods and do best on small live or frozen items — Artemia, Daphnia, bloodworm and glassworm — offered after lights-out so the naturally shy, nocturnal fish is not out-competed by more active tankmates. There is no aquarium-specific feeding record for clinatus itself, so this account follows genus-level care guidance rather than species-specific observation.
Mating
No courtship or spawning behaviour has been documented for Akysis clinatus in the wild or in captivity. Data on reproduction in the genus Akysis as a whole is thin: aquarium breeding has essentially not been achieved for most species, and the tiny size and specialised stream habitat of clinatus in particular make it an unlikely candidate for hobbyist observation.
One genus relative, Akysis vespa, has been spawned in captivity under simulated rainy-season conditions — a cold water change and soft water triggering the male to wrap around the female — but fry-rearing was not established even in that case, and there is no indication this has been replicated for clinatus or most other congeners. Given the complete absence of trade presence and published breeding accounts, this species' mating behaviour should be treated as unknown.
Breeding
There is no record of Akysis clinatus being bred in aquaria, and given how rarely — if ever — this species has even been kept outside of scientific collections, that is unsurprising. It is honest to say breeding is simply undocumented rather than to guess at a mode.
What can be said is that it should not be assumed to follow an open-water egg-scattering pattern by default: small hillstream akysids that have been observed (such as A. vespa, above) show more complex courtship involving a female-wrapping male and a cool, soft-water spawning trigger tied to seasonal rains. If clinatus follows this genus pattern, any parental care would likely be minimal to absent post-spawning, but this remains speculative extrapolation from a relative, not a documented fact about the species itself.
In the aquarium
Akysis clinatus is not established in the aquarium trade and has no common name in general use — this profile exists primarily as a taxonomic and conservation record rather than a care guide from direct experience. Should it ever appear, it should be treated exactly like its better-known genus relatives: a genuinely tiny adult (around 1 in), so it must never be judged as "just a juvenile" and stocked accordingly — a group of these fish needs only a modest footprint, but a very stable, clean, well-oxygenated one.
Three points carry over directly from the genus: it is completely scaleless, so treat any medication — copper in particular — conservatively; it wants clear, cool, fast-flowing, well-oxygenated water rather than a warm, still community tank; and as a nocturnal forager it needs shelter (fine gravel, smooth stones, gentle flow) and is best fed live or frozen foods after dark. Given the total lack of trade history, sourcing would almost certainly mean wild-collected fish from a very restricted Cambodian range — a strong argument against collecting it at all.
Conservation
The IUCN Red List has not published a numeric species-specific assessment page with a stable URL that was found in the sources consulted for this profile; based on available search results the species' status is treated here as Data Deficient, consistent with its extremely narrow known range and the almost complete absence of follow-up survey work since its 2005 description.
Akysis clinatus is known only from the Stung Chhay River in southwestern Cambodia, a small Gulf-of-Thailand-draining basin. Single-river endemics in this region face generic but real pressures — deforestation, agricultural runoff, damming and stream degradation — that are common threats to small-range Southeast Asian hillstream fishes, though no pressure has been specifically documented for this species. Its restricted range alone is reason for caution, and given the total absence of any trade presence, there is no evidence the aquarium hobby has ever placed collection pressure on it.