The striped catfish, Pangasianodon hypophthalmus, is a freshwater fish species belonging to the family Pangasiidae, commonly known as shark catfishes. It is naturally found in the extensive river basins of Southeast Asia, particularly within the Mekong and Chao Phraya river systems.
The species is known for its migratory behavior, undertaking long-distance movements between different habitats for spawning and feeding. These migrations are often triggered by seasonal changes in water levels, with fish moving upstream to spawn during certain periods and returning downstream to feeding grounds.
Appearance and Natural Habitat
In its natural riverine environment, the striped catfish exhibits distinct physical characteristics that change with age. Juvenile specimens display two prominent dark stripes running horizontally along their body: one along the lateral line and another below it. As the striped catfish matures, these distinct stripes gradually fade, and the adult fish develops a more uniform silvery-grey coloration.
Mature individuals in nature can reach lengths of up to 130 centimeters (over four feet) and weights up to 44 kilograms. The natural habitat of Pangasianodon hypophthalmus spans the Mekong and Chao Phraya river systems across countries like Thailand, Laos, Cambodia, and Vietnam.
These fish are omnivorous, consuming a varied diet that includes algae, zooplankton, insects, and higher plants, with larger specimens also preying on fruit, crustaceans, and smaller fish. They are also highly active schooling fish, preferring to live in groups in open water environments.
The Striped Catfish in Aquaculture
The striped catfish is a major global food source, widely farmed across Southeast Asia. In the food industry, it is marketed under commercial names such as “Swai,” “Basa,” or “Pangasius,” making it a significant competitor in the global whitefish market.
Large-scale aquaculture operations, particularly in Vietnam, dominate its production. The farming process begins with induced spawning, followed by transferring larvae to nursery ponds. Juveniles are then moved to grow-out ponds, often stocked at densities of 60–80 fish per square meter.
The popularity of the striped catfish in aquaculture stems from its rapid growth rate, mild flavor, and cost-effectiveness. Its diet primarily consists of grain-based ingredients. The fish’s ability to breathe atmospheric oxygen allows for high stocking densities, contributing to its economic viability in pond culture.
Keeping Striped Catfish in Aquariums
The striped catfish is frequently sold to aquarium hobbyists, typically when it is only a few inches long, under the common name “Iridescent Shark.” However, its suitability for the vast majority of home aquariums is quite limited. These fish grow rapidly and can easily exceed a foot in length within their first year, quickly outgrowing smaller tanks.
An adult Pangasianodon hypophthalmus can reach over four feet in length and requires an exceptionally large tank, with a minimum of 300 gallons for a single adult and ideally 150 gallons for each additional fish if kept in a group. Their natural schooling behavior means they are less shy and more comfortable when maintained in groups, which further increases the space requirements.
The species is also known to be quite skittish, especially in smaller or brightly lit tanks, often darting suddenly and potentially injuring themselves by colliding with tank decorations or glass. Providing appropriate water parameters, including temperatures between 22-26°C and a pH of 6.5-7.5, is also necessary, but the sheer size and waste production of these fish necessitate powerful filtration and regular, large water changes. Due to these extensive needs, keeping an iridescent shark represents a significant long-term commitment that most home aquarists cannot adequately provide, often leading to a shortened lifespan for the fish.