Pangasianodon hypophthalmus is one of the most widely recognised and most commonly mistreated catfish in the aquarium hobby. Sold as small, shiny juveniles with dazzling iridescent flanks, this pangasid catfish grows rapidly into a large, powerful fish capable of exceeding one metre in length. In the wild it is a migratory species forming enormous schools in the Mekong River drainage of Thailand, Laos, Cambodia, and Vietnam.
In the aquarium, Iridescent Sharks require very large facilities even as sub-adults. They are exceptionally skittish and prone to crashing into glass when startled, frequently damaging themselves in undersized tanks. They are best kept in large groups of their own kind — six or more — to reduce individual nervousness. Mature specimens are imposing, fast-moving fish that must be treated with considerable respect.
This species is an omnivore that accepts a wide range of foods including large sinking pellets, whole prawns, earthworms, and plant matter. Despite its demanding requirements, the Iridescent Shark remains one of the most popular large catfish due to its striking juvenile colouration and the enduring appeal of its juvenile form. Responsible purchase requires commitment to long-term accommodation of a very large fish.
