Taxonomy & naming
Pseudomystus heokhuii Lim & Ng, 2008 is the valid name in the Catalog of Fishes. It was described from Rantau Panjang in the Batang Hari drainage, Jambi, Sumatra. The epithet is a patronym; the original dedication is not given in the sources available to the atlas.
Morphology
Pseudomystus are small bagrid catfishes of South and Southeast Asia, with a short adipose fin, four pairs of barbels, a serrated spine at the front of the dorsal and pectoral fins, and a body marked with pale and dark bands or stripes in most species. FishBase gives this species a maximum of 2.5 in SL.
Habitat
FishBase gives its range as the Batang Hari and Indragiri River drainages in Sumatra. It occurs in floodplain channels and peat swamps with very acidic, tannin-stained water of pH 3.5 to 4.5.
Feeding
Bagrids of this genus are nocturnal carnivores and omnivores that take insects, crustaceans, worms and small fish. Species-level diet data are not recorded in the sources available to the atlas. In captivity they accept frozen foods, live worms and meaty sinking pellets.
Mating
Mating behaviour is not recorded in the sources available to the atlas.
Breeding
Captive breeding of this species is not recorded in the sources available to the atlas.
In the aquarium
Offer plenty of caves and dark retreats; the fish are shy by day and active after dark. Avoid keeping them with fish small enough to be swallowed. Handle with care because of the pectoral and dorsal spines. FishBase records it at pH 3.5 to 4.5, so soft, acidic, tannin-stained water is the appropriate model; no temperature or hardness range is given.
Conservation
The IUCN Red List lists it as Endangered, meaning it faces a very high risk of extinction in the wild. FishBase gives no assessment year. Peat swamps and lowland forest streams in its range are being cleared and drained.