Taxonomy & naming
Pangasius pangasius was described by the Scottish physician and naturalist Francis Hamilton (writing as Francis Buchanan-Hamilton) in 1822, based on specimens from the Ganges river system. It is the type species of the genus Pangasius, established within the family Pangasiidae, the shark catfishes. Older literature sometimes shuffled species among the historically unstable Siluriformes genera of the period, but the Catalog of Fishes (Eschmeyer, California Academy of Sciences) confirms Pangasius as valid and Pangasius pangasius as the type species anchoring the genus.
The genus and species name Pangasius derives from a local Bengali/Assamese vernacular name for the fish, later Latinised for scientific use — a naming pattern shared with several other South and Southeast Asian catfish genera. The family Pangasiidae is distinguished from other catfish families by its shark-like silhouette: a forked tail, streamlined body and prominent dorsal fin that together give the group its "shark catfish" common name, despite no relation to actual sharks.
Morphology
Pangasius pangasius has the classic pangasiid build: a laterally compressed, streamlined body, a deeply forked caudal fin, a tall triangular dorsal fin with a stiff leading spine, and long paired barbels on the upper jaw used to probe the riverbed. Like all catfish it is scaleless, with smooth, naked skin rather than scales — a trait that matters directly for aquarium medication, since scaleless fish absorb many treatments, especially copper-based ones, more readily than scaled fish and must be dosed conservatively.
FishBase records a maximum standard length of 59–118 in for this species, making it one of the larger Pangasiidae — smaller than the true giant, Pangasianodon gigas, but still a genuine river giant. The dorsal and pectoral fins carry stiff, serrated, locking spines that can jam erect and catch in a net; larger individuals should always be moved in a container rather than netted, both to protect the fish and to avoid a jab to the handler.
Habitat
This species is native to the fresh and brackish waters of major South Asian river systems: the Ganges, Krishna and Godavari basins in India, along with river drainages in Bangladesh, Myanmar and Pakistan. It has also been documented, likely via introduction, in parts of Cambodia and Vietnam. FishBase notes it as potamodromous, migrating within fresh water to spawn, and occurring at depths greater than 50 metres in the larger river channels and associated waters.
Water conditions across its native range are warm, tropical and only mildly mineralised: FishBase gives a temperature range of roughly 73–82 °F and pH 6.0–7.5, consistent with the large lowland river and estuarine systems of the Indian subcontinent. It tolerates brackish conditions in the tidal reaches of these rivers, reflecting its life history moving between freshwater and estuarine habitats.
Feeding
Pangasius pangasius is an opportunistic omnivore with strong carnivorous tendencies as it grows. FishBase records a diet of plant matter, shrimp, molluscs and worms in the wild, and larger individuals are capable predators that will take any fish or invertebrate small enough to swallow. This is a fish that eats its tankmates rather than coexisting with them once it reaches any size.
Where juveniles are kept, they accept sinking pellets, prepared carnivore diets and meaty foods such as prawn and fish pieces readily, and grow quickly on a generous feeding schedule — another reason the size trap catches unprepared keepers so fast. Any companion species must be far too large for this catfish to swallow, which in practice rules out all but the largest tankmates.
Mating
Pangasius pangasius is a potamodromous migratory spawner: FishBase records that it breeds in estuaries during the rainy season, moving from its river habitat into brackish, tidally influenced water to spawn in response to seasonal flooding. This life-history pattern, tied to monsoon hydrology and river connectivity, is entirely wild and not something replicated in a home tank.
As with other large Pangasiidae, reproduction in captivity is achieved commercially through hormone-induced spawning at aquaculture facilities rather than natural pairing, and the species has never been bred in a home aquarium — nor could it be, given the tank volumes and migratory triggers involved.
Breeding
This is a farm- and hormone-bred species at commercial scale, produced in South Asian aquaculture operations using induced spawning with hormone injections to trigger release of eggs and milt outside the fish's natural monsoon migration window. It is essentially never bred in the home aquarium: adult broodstock require pond or tank volumes measured in thousands of litres, and the natural spawning trigger is tied to seasonal river and estuarine conditions that cannot be reproduced domestically.
Hobbyists should not expect to breed this species and should not acquire it with breeding in mind. Any specimen kept in a home aquarium will, if it survives and grows, remain a permanently non-reproducing individual housed purely for observation, not for a breeding project.
In the aquarium
The single most important fact for any prospective keeper is size: Pangasius pangasius reaches 59–118 in in the wild, and even aquarium-raised individuals commonly exceed a metre in length. It is routinely sold as an inexpensive, active silvery juvenile a few centimetres long, and just as routinely outgrows every home aquarium within a couple of years — the size trap that catches this genus more than almost any other in the trade. No standard home tank can house an adult; this is fundamentally a public-aquarium, large pond, or wild-river fish, not a home aquarium species, and it should not be purchased without a realistic plan for a several-thousand-litre final home.
Where young fish are kept short-term, water should be warm (73–82 °F) and near-neutral (pH 6.0–7.5), with strong filtration and swimming space, since this is a fast, nervous, schooling-by-nature fish prone to bolting and injuring itself against tank glass or décor. Its scaleless skin means medications, particularly copper-based treatments, should be dosed conservatively. Its dorsal and pectoral spines can lock and snag a net, so larger fish should be moved in a container. Tankmates must be robust and far too large to be eaten. Given the near-certainty of outgrowing captivity, most responsible retailers and keepers now discourage buying this species at all outside of public aquarium or large-scale aquaculture contexts.
Conservation
The IUCN Red List assessed Pangasius pangasius as Least Concern in 2022. The species remains abundant across most of its range and supports significant food and sport fisheries in India, Bangladesh, Myanmar and Pakistan.
Despite the overall LC status, the assessment notes population declines in parts of the Ganges and Brahmaputra systems, driven by fishing pressure for food and sport, damming and other river infrastructure that disrupts the potamodromous migrations this species depends on for spawning, and pollution of lowland river and estuarine habitats. Its conservation outlook is therefore tied closely to the health and connectivity of the major South Asian river systems it inhabits, even though the species as a whole is not currently considered threatened.