Taxonomy & naming
Ompok brevirictus was described in 2009 by Heok Hee Ng and Renny Kurnia Hadiaty in Zootaxa (2232(1): 50-60), as a new catfish from Sumatra. It belongs to the family Siluridae — the true glass and sheatfish catfishes of Europe, Africa and Asia — and to the genus Ompok, a group of South and Southeast Asian river sheatfishes that ranges from small, aquarium-sized species up to much larger pond-scale fish.
The species epithet brevirictus comes from Latin brevis, "short", and rictus, "mouth" or "gape", referring to the relatively short mouth that helps distinguish it from other Sumatran Ompok. It is separated from its congeners chiefly by its evenly convex predorsal profile and details of the jaw structure. As a recently described, narrow-endemic species, it has not undergone any genus-level reshuffling since its description and is treated under Ompok by the Catalog of Fishes.
Morphology
Ompok brevirictus is a small, laterally compressed sheatfish reaching a documented maximum of about 5 in standard length, making it one of the more modestly sized members of its genus. Like all Siluridae it is scaleless, with smooth, naked skin — a trait that matters directly for aquarium medication (see "In the aquarium"). The body shows the typical Ompok silhouette: an evenly convex back running from head to dorsal fin, a long anal fin, and barbels used to feel out food in low light or murky water.
Detailed morphometric data for this species is sparse in publicly available sources beyond the original description, which emphasises its short mouth (rictus) and predorsal profile as the key features separating it from other Sumatran Ompok such as O. bimaculatus and O. siluroides.
Habitat
The type locality lies in short coastal rivers draining the western face of the Leuser Mountain Range in Nangroe Aceh Darussalam province, northern Sumatra, Indonesia — specifically the Krueng Kluet (Kluet River) drainage, which empties into the Indian Ocean. This places the species in fast-draining montane-to-lowland river systems rather than the vast blackwater basins associated with many other Sumatran fishes.
Detailed water chemistry data specific to O. brevirictus has not been published; the species is known primarily from its original description and IUCN assessment. Data is sparse beyond the type locality, and its ecology within these short Sumatran rivers remains poorly documented.
Feeding
No species-specific dietary data has been published for Ompok brevirictus. Sheatfishes in the genus Ompok are generally omnivorous to predatory mid-water feeders, taking small fish, invertebrates and other food items opportunistically; related, better-studied Ompok species are reported to be resilient feeders that adapt to a range of prepared and meaty foods in captivity.
Given the total absence of aquarium accounts for this specific species, any feeding regime for O. brevirictus would have to be extrapolated cautiously from its genus rather than drawn from direct observation.
Mating
No spawning or courtship behaviour has been documented for Ompok brevirictus in the wild or in captivity. Glass and sheatfish catfishes as a group are essentially unstudied or unbred in the aquarium trade — the small glass catfishes of the related genus Kryptopterus are supplied almost entirely from wild collection rather than captive breeding, and larger river-dwelling Ompok and Wallago species that are bred at all are produced through farm or hormone-induced spawning rather than natural aquarium pairing.
There is no published account of O. brevirictus courtship, and given its very recent description (2009) and narrow, poorly surveyed range, none should be assumed.
Breeding
Home aquarium breeding of Ompok brevirictus is not established and there is no evidence it has ever been bred in captivity. As with other members of Siluridae, larger river-spawning Ompok and Wallago species that do reproduce under human care are typically farm- or hormone-bred at commercial scale for food-fish or fry production, not spawned naturally in home tanks. Smaller glass catfishes in the family are, if anything, even less amenable to captive reproduction and the aquarium trade for them relies on wild-caught stock.
Given this species' Endangered status and its total absence from the aquarium hobby literature, there is no realistic prospect of home breeding, and any aquarium specimens in circulation — if the species is traded at all — would be wild-collected from its narrow Sumatran range.
In the aquarium
Ompok brevirictus is not an established aquarium fish, and hard husbandry data for the species itself could not be confirmed. What can be stated with confidence: at roughly 5 in standard length it is one of the smaller members of its genus, but keepers should still be cautious with any Ompok species, since several congeners sold as small juveniles grow into pond- or public-aquarium-scale fish that quickly outgrow a home tank — always confirm the adult size of any Ompok before buying.
Like all Siluridae, this species is scaleless, so it should be treated as medication-sensitive: copper-based treatments and many standard medications should be dosed conservatively, often at half strength, as with loaches, puffers and true eels. General care notes drawn from related Ompok (not confirmed for this species specifically) suggest warm, well-oxygenated, flowing water in the roughly 68–81 °F range with a near-neutral to slightly alkaline pH, reflecting their fast-draining river habitat. Given the complete lack of trade or care records, this species should be regarded as effectively unavailable in the hobby rather than a realistic stocking choice.
Conservation
The IUCN Red List assesses Ompok brevirictus as Endangered (EN), under criterion B1ab(iii), based on an assessment dated 1 September 2018. The listing reflects its extremely restricted range: the species is known only from short coastal rivers draining the western Leuser Mountains of northern Sumatra, a limited area subject to ongoing habitat pressure.
As a narrow-range Sumatran endemic described only in 2009, O. brevirictus has had little time to be surveyed or monitored, and its population trend and the specific threats it faces beyond restricted range are not detailed in the sources available here. It is not known to be part of the aquarium trade, so collection pressure is not identified as a driver of its threatened status; habitat degradation within its small native range is the implied concern.