Taxonomy & naming
Pangasius conchophilus was described by Tyson R. Roberts and Chavalit Vidthayanon in 1991, part of their broader revision of the shark catfish family Pangasiidae in Southeast Asia. It belongs to the genus Pangasius within the family Pangasiidae, the shark catfishes, and the Catalog of Fishes treats Pangasius conchophilus as the currently valid name with no reshuffling into another genus.
The species epithet conchophilus comes from Greek/Latin roots meaning "shell-loving", a direct reference to its adult diet of molluscs and other shelled invertebrates picked up from the riverbed. It is one of many Pangasius species native to the Mekong system that are easily confused as juveniles — silvery, streamlined, sold at a few centimetres long under generic "iridescent shark" or "pangasius" trade names — with definitive identification usually requiring an adult or a specialist.
Morphology
Like other Pangasius, this species has the classic shark catfish silhouette: a streamlined, laterally compressed, silvery body, a deeply forked tail, a tall pointed dorsal fin with a hardened leading spine, and long paired barbels on the upper jaw. The skin is scaleless (naked), like all catfishes, which has direct consequences for how it should be medicated.
FishBase records a maximum size of 47 in for Pangasius conchophilus, and field data from the Mekong show clear size classes tied to its migratory life history: juveniles recruit into floodplain nursery habitat at only 1–3 in, fish making the non-spawning downstream/upstream movements run roughly 4–15.5 in, and mature adults on their spawning migration run 15.5–35.5 in and larger. The dorsal and pectoral fins carry stiff, serrated, locking spines typical of the family — they can jam in a net and jab a careless hand, so this is a fish to move in a container rather than net, even at a modest juvenile size.
Habitat
Pangasius conchophilus is native to the Mekong basin and also recorded from the Bangpakong and Chao Phraya basins of Thailand — large, warm, tropical Southeast Asian river systems. It is benthopelagic and potamodromous, meaning it lives near the bottom and mid-water column and undertakes its entire life cycle within fresh water, migrating within the river system rather than to the sea.
It occupies a range of mainstem and floodplain habitats through its life: flooded forests and shallow floodplain margins as a recruit, then the main channel, deep slow reaches and rapids as it grows and joins the seasonal migratory runs that are characteristic of Mekong pangasiids. Farmed water-quality guidance for the genus gives a practical working range of roughly pH 6.5–7.5 and 77–86 °F, consistent with the warm, circumneutral conditions of its native lowland rivers; this is not a soft, acidic blackwater species.
Feeding
The common name gives away the adult diet: subadults and adults feed heavily on molluscs, together with prawns and aquatic insects, picked from the substrate — a durophagous, invertebrate-heavy diet distinct from the more general omnivory of some other Pangasius. Younger juveniles start out on prawns and insect larvae before shifting toward the mollusc-heavy diet as they grow, and plant material is also taken opportunistically.
In practice this is a large predatory/invertebrate-feeding catfish, not a fish that can be kept on flake alone. Aquarium reports describe it accepting flakes, spirulina flakes and prawns, but any keeper taking one on should plan around meaty, substantial foods — whole prawn, mussel or snail, and large sinking pellets — and should assume it will eat any tankmate small enough to swallow.
Mating
There is no record of natural courtship or pairing behaviour for this species in the aquarium literature, and that absence is itself informative: Pangasius conchophilus is a large, commercially important migratory catfish whose reproduction in captivity is achieved entirely through hormone induction, not through natural pair formation. In the wild, adults make a spawning migration upstream in the Mekong system, running roughly 15.5–35.5 in, timed to the rains (reported migration window May–August); actual spawning sites and natural courtship behaviour are poorly documented, as is typical for a big, fast-moving river fish that is far easier to study at hatcheries than in the field.
Commercial hatchery practice bypasses natural mating altogether: ripe broodstock are selected and injected with hormones (HCG, carp pituitary gland extract, or buserelin combined with domperidone) to trigger ovulation, and eggs are then stripped and fertilised by hand. This is standard aquaculture procedure for the genus and is the only reproductive pathway documented for this species.
Breeding
Pangasius conchophilus is farm- and hormone-bred at commercial scale and is essentially never bred in the home aquarium — it grows far too large for a hobbyist tank to hold a mature broodstock pair, and reproduction depends on induced spawning that only a hatchery can deliver. Published hatchery data describe ovulation occurring roughly 10–12 hours after a hormone injection, with eggs hatching in about 24–25 hours at 82 °F.
Once hatched, hatchery-reared fry are raised on live prawns and insect larvae before graduating to the mollusc-and-prawn diet of subadults. There is no parental care of any kind — eggs are stripped from the female and fertilised artificially, and larvae are reared in hatchery tanks with no adult involvement. Any aquarist encountering this species should treat it purely as a food-fish/aquaculture species from a breeding standpoint, not as a candidate for a home breeding project.
In the aquarium
This is a genuine size-trap fish. Pangasius conchophilus is sold in the trade as a small, inexpensive, streamlined silver juvenile a few centimetres long, but FishBase gives a maximum size of 47 in — a fish that, if it survives, will outgrow essentially every home aquarium and needs a very large pond, holding facility, or public display tank. Prospective keepers should assume this is not a lifetime home-tank fish and should not buy a juvenile without a realistic plan for what happens once it reaches even a third of that length.
Beyond size, care follows general shark-catfish and catfish rules: the skin is scaleless, so it is more sensitive than scaled fish to copper-based medications and many treatments — dose conservatively. It carries stiff, locking dorsal and pectoral spines that can snag a net and injure the handler, so move it in a container rather than netting it. It is an active, schooling-by-nature river fish prone to panicking and injuring itself against glass or décor in a confined space, and as a substantial predator/invertebrate-feeder it will eat any tankmate small enough to swallow — anything sharing its water needs to be too large to fit in its mouth. Reports note it is sensitive to sudden water-chemistry swings but otherwise disease-resistant.
Conservation
The IUCN Red List assesses Pangasius conchophilus as Least Concern, reflecting its wide distribution across the Mekong, Bangpakong and Chao Phraya basins and its status as an economically important, well-studied aquaculture and fisheries species rather than a narrow-range endemic.
That said, Least Concern at the species level does not mean the wild population faces no pressure: Mekong pangasiids as a group are affected by mainstem damming, which can block or disrupt the long spawning migrations this species depends on, along with overfishing and habitat loss in floodplain nursery areas. Much of the trade and food-fish supply now comes from hatchery-bred stock rather than wild capture, which reduces direct collection pressure even as the wild migratory population remains exposed to river-scale threats.