Taxonomy & naming
Acrochordonichthys rugosus was described by Pieter Bleeker in 1846, from Java, and the Catalog of Fishes lists it as valid in the family Akysidae, the Asian stream catfishes. It is a stock-in-trade species for stores that deal in oddball Southeast Asian catfishes and appears under its scientific name.
The name describes the skin: the genus name joins the Greek for wart with the Greek for fish, and the epithet is Latin for wrinkled.
Morphology
The body is rough and tubercled, with the warty, wrinkled skin that gives the genus and species their names, and the head is broad and flattened with small eyes and four pairs of barbels, as in other akysids. FishBase gives a maximum of 4.5 in SL.
Habitat
FishBase records the species from Thailand, Malaysia and Indonesia, with Java the type locality. It lives in clear, swiftly flowing forested streams over sand or rock, where it hides under submerged logs and rocks and in leaf litter in the faster stretches. FishBase gives a pH of about 7 for the streams it inhabits.
Feeding
It is a predator that ambushes its prey from cover. FishBase notes balitorid loaches of the genus Nemacheilus and sisorid catfishes of the genus Glyptothorax among the fish it takes, so small fish and large invertebrates are the working diet in the aquarium too.
Mating
The mating system is not described in the sources the atlas draws on. Akysid catfishes as a group fertilise internally, but that has not been documented for this species.
Breeding
No spawning, egg or fry observations are recorded for Acrochordonichthys rugosus, and it is not known to have been bred in captivity.
In the aquarium
Keep it in a cool, well-oxygenated tank with strong water movement, a sand or fine gravel floor and plenty of wood, rock and leaf litter for daytime shelter. It is a nocturnal ambusher, so tankmates should be too large to swallow: anything small enough to fit in its mouth, including shrimp and young loaches, is food. Offer live or frozen fish and invertebrate foods; it is not an easy fish to wean onto dry diets. Few stores carry it and wild-caught fish are the norm.
Conservation
The IUCN Red List assessed Acrochordonichthys rugosus as Least Concern in 2018. No specific threats are recorded in the sources the atlas uses, and the species is wide ranging across the Sunda region. Like other forest stream fishes it depends on clear, well-oxygenated water, which logging and silt can degrade.