Taxonomy & naming
Ompok leiacanthus was described by the Dutch ichthyologist Pieter Bleeker in 1853. It belongs to the family Siluridae, the Old World sheatfishes, a family that also contains the glass catfishes (Kryptopterus), the giant wels and its relatives (Silurus) and the giant Wallago. The genus Ompok holds a couple of dozen species distributed across South and Southeast Asia.
The research cache found no historical synonym for this species under Silurus or Callichrous, the older genera into which many Siluridae were once lumped; Ompok appears to be its original and current combination. As with much of Siluriformes, the family has been repeatedly reshuffled by modern taxonomic revisions, so the genus placement of related species should always be checked against the Catalog of Fishes rather than assumed from older aquarium literature.
Morphology
Ompok leiacanthus has the classic sheatfish silhouette: a long, laterally compressed, scaleless body, a long-based anal fin, a small dorsal fin set well forward, and a forked tail. Like its relatives it carries long, whisker-like barbels used to feel out food and surroundings in low light or murky water.
The formal maximum size on record is 7.5 in total length, but this is a marked understatement of what the species can reach outside the record books: aquarium and field reports describe animals up to roughly 18 inches (about 17.5 in), with 8 inches (about 8 in) common even in captivity after a few years of growth. Prospective keepers should plan around the larger figure, not the smaller one — this is the central size trap with this genus. The skin is naked and scaleless, which has direct consequences for how the species should be medicated (see "In the aquarium").
Habitat
The species is native to Sumatra, with records spanning Indonesia, Malaysia and Brunei. It lives in shallow, clear, tropical freshwater streams and is described on FishBase as demersal, i.e., typically found near the bottom, although in practice it is also reported swimming actively at mid-water levels — an unusual habit for a catfish.
The cache does not give precise pH, hardness or temperature figures beyond "tropical freshwater stream" conditions. What is recorded is that the species is resilient to shifts in temperature and water parameters and can adapt to both fresh and brackish water, suggesting a hardy generalist rather than a chemistry specialist. Given the sparse data, keepers should aim for stable, well-oxygenated, warm tropical stream conditions rather than assume a narrow or extreme parameter range.
Feeding
Ompok leiacanthus sits at a trophic level of roughly 3.7 on FishBase's scale, consistent with a carnivore, and hobby sources describe it plainly as piscivorous — an eater of fish and invertebrates. In the wild it likely takes any prey items it can overpower and swallow whole.
In the aquarium it accepts meaty foods: whole fish, prawn and shrimp, and quality sinking pellets. Because it forages and feeds unusually high in the water column and even at the surface for a catfish, food does not need to be exclusively bottom-delivered. Any tankmate small enough to fit in its mouth should be considered at risk, and stocking should be planned accordingly.
Mating
No courtship or spawning behaviour for Ompok leiacanthus is documented in the available sources; the cache explicitly notes that breeding data is sparse for this species on FishBase. Among its Siluridae relatives, the smaller glass catfishes (Kryptopterus) are essentially never bred in captivity and the trade in them remains wild-caught, while the larger sheatfishes such as Wallago and Silurus are river spawners that are mostly produced at commercial or farm scale rather than in home tanks.
Ompok leiacanthus has not been reported to spawn in aquaria, and there is no evidence in the sources of any distinct courtship display, pairing behaviour, or spawning trigger having been documented for the species.
Breeding
There is no established aquarium breeding protocol for Ompok leiacanthus, and the fish available in the trade should be assumed to be wild-caught or, at best, collected as juveniles from natural Sumatran waters rather than captive-bred. This mirrors the pattern across most of the Siluridae kept in aquaria: the family's celebrated home-breeding successes are concentrated in unrelated groups (armoured callichthyids with their bubble nests, or the brood-parasitic Synodontis multipunctatus among the Mochokidae), not among the sheatfishes.
Hobbyists should not expect this species to spawn in a standard aquarium setup, and no parental care behaviour has been recorded for it. Anyone acquiring the species should do so understanding that the supply chain depends on wild or semi-wild collection rather than captive propagation.
In the aquarium
The headline care point is size: Ompok leiacanthus is routinely sold as a small, unassuming juvenile a few centimetres long, but field and hobby reports put its real ceiling at around 17.5 in, with 8 in a realistic expectation even in captivity, achieved over a period of years. A tank purchased for a young specimen will not remain adequate — this is a fish that needs to be planned for at its adult size, and most home aquaria are not a long-term fit for it. Provide strong filtration and turnover; hobby sources recommend roughly ten times the tank volume in filtration turnover per hour, reflecting the species' need for clean, well-oxygenated, moving water reminiscent of its stream habitat.
Two further care notes follow directly from its biology. It is a scaleless catfish, so like loaches, puffers and eels it is more sensitive than scaled fish to copper and to many medications — treat conservatively and consider a reduced dose when medicating a tank that holds this species. It is also reported to be a jumper when startled or excited, so a tight-fitting lid is worth the trouble. Behaviourally it is unusual among catfish for swimming actively in mid-water and feeding near the top rather than hugging the substrate, and it is reported to tolerate both fresh and brackish conditions. Because it is a genuine piscivore, tankmates must be too large for it to swallow; anything smaller should be treated as prey rather than as a companion.
Conservation
The IUCN Red List assessed Ompok leiacanthus as Near Threatened in 2019. As a Sumatran endemic with a comparatively restricted island distribution, it is more exposed to localised pressures — habitat degradation, water quality decline and stream modification — than a widely distributed mainland species would be.
The cache does not detail the specific drivers behind the Near Threatened listing, but Sumatra's freshwater streams face well-documented pressure from deforestation, agricultural conversion and development, all of which can degrade the clear, shallow stream habitat this species depends on. Because the aquarium trade appears to draw on wild or semi-wild stock rather than captive breeding, collection pressure is a plausible additional factor worth monitoring, even though the sources available here do not quantify it.