Taxonomy & naming
Pieter Bleeker described the species in 1864, and the parentheses around the authority show that it began in a different genus. The Catalog of Fishes lists Tachysurus dumerili as valid, and gives no type locality. Tachysurus now holds many East Asian bagrids that older books placed in Pseudobagrus and related genera, so older literature may use other names for fish in this group.
Morphology
FishBase gives a maximum length of 31.5 in TL, which makes it one of the larger East Asian bagrids. The body is elongate, the head broad and depressed, and four pairs of barbels surround the mouth, as in other bagrids. A stiff spine at the front of the dorsal and pectoral fins can lock erect.
Habitat
FishBase lists the species from China and Korea, in freshwater and brackish water, living near the bottom in a temperate climate. It gives no temperature or pH range.
Feeding
FishBase has no diet entry. Large bagrids in general are carnivores taking fish, crustaceans and insects, and a fish of this size in the aquarium would eat meaty foods.
Mating
Courtship and spawning behaviour are not recorded for this species.
Breeding
Breeding is not recorded in FishBase for this species.
In the aquarium
A fish that can reach 31.5 in needs a tank far larger than most homes hold, and it will eat tankmates that fit in its mouth. Its temperate origin means it does not need tropical heat. Unless a keeper can offer a pond or a very large aquarium, this is not a species to buy as a juvenile.
Conservation
IUCN lists the species as Data Deficient, assessed in 2007. No population trend is recorded.