Swai fish, also commonly known as iridescent sharks, are a type of shark catfish that are native to Vietnam.

These omnivorous bottom feeders live in the Mekong river and migrate upstream when the water levels rise in the late summer. When left to their own devices, iridescent sharks can get as big as 100 pounds. Commercial farmers frequently breed large quantities of swai to sell as a popular replacement for catfish meat. You can also find small iridescent sharks that have been stunted in growth to serve as aquarium pets.

3 Incredible Swai Fish Facts!

• Glowing fins: The iridescent shark’s name comes from the edges of its fins, which have a shimmery glow that is visible even in the dark.
• Endless appetite: Swai are known for eating nearly any kind of food they come across. Plants, crustaceans, and smaller fish are no match for the iridescent shark’s omnivorous appetite.
• Sharkfin style: Swai are a type of pangasius, or shark catfish. Although they’re not actually sharks, these catfish all feature a dorsal fin and a silvery, shark-like appearance.

Swai Fish Classification and Scientific Name

The scientific name for swai fish is Pangasianodon hypophthalmus. In Vietnam, they are often referred to as tra fish; they may also be mistaken for the related basa, or Pangasius bocourti. When they’re not being sold as livestock, these silver creatures are frequently called iridescent sharks for their glowing fins and shark-like appearance.

Iridescent sharks belong to the Actinopterygii class and Pangasiidae family of shark catfish. They are related to American catfish, but they are distinguished by their shark-like dorsal fins. In reference to their scientific name, shark catfish are also frequently called pangasius by members of the research community.

Swai Fish Appearance

Iridescent sharks are a type of Asian catfish with silver scales, beige skin, and small whiskers. Like other shark catfish, pangasius have a small dorsal fin on the top of their bodies. The edges of a pangasius’ fins glow faintly underwater, making them a popular choice for aquariums.

Young iridescent sharks can grow to be anywhere from 1 to 4 feet long and typically weigh between 50 to 100 pounds. The largest ever recorded swai fish weight 44 kilograms, or about 97 pounds. The growth of a pangasius can be stunted by diet or a confined space, which is why iridescent sharks that live in aquariums are usually so much smaller than their wild or commercially-grown counterparts.

Swai Fish Distribution, Population, and Habitat

Iridescent sharks are native to Asia and are most commonly found within the country of Vietnam. Most wild pangasius lives in the Mekong river, where they swim upstream from the Maeklong basin. Some pangasius also swims downstream into the Chao Phraya.

Pangasius are freshwater fish and are popularly farmed in ponds, rice paddies, and similar structures. Nearly all commercially sold iridescent sharks are bred as livestock; you shouldn’t expect to purchase a wild pangasius at a normal market. Although population numbers are not available, iridescent sharks are considered to be endangered in their natural habitats.

Swai Fish Predators and Prey

Iridescent sharks are omnivorous animals that feed on crustaceans, algae, bugs, and other small fish. A swai will eat nearly anything it can catch as it grows to its full size of 100 pounds. When they are farmed commercially, pangasius is typically fed a diet that consists of barley, oats, and other types of grain.

Pangasius has no natural means of self-defense, making them a popular target for all predatory animals in their native region, including birds, mammals, and other large fish. Human fishermen are one of the primary threats to iridescent sharks, and overfishing is likely responsible for their current status of endangered.

Swai Fish Reproduction and Lifespan

Iridescent sharks are egg-laying creatures that live in large clusters. Like other types of catfish, pangasius breed in a migratory pattern that involves swimming upstream to a breeding ground during the late summer months.

Due to their wild nature, iridescent sharks are particularly difficult to breed in captivity. Pangasius farmers tend to keep the fish in large ponds with many other members of the same species to ensure adequate breeding conditions. Due to the lack of research on this particular type of fish, it is unknown how long a swai might live in the wild. In captivity, a well-loved iridescent shark might manage to have a lifespan as long as twenty years.

Swai Fish in Fishing and Cooking

Although iridescent sharks are found naturally in the rivers of Vietnam, most commercial swai production takes place in controlled farming environments. Large groups of pangasius are kept in ponds, rice fields, and other watery areas until they are big enough to harvest for consumption.

In cooking, swai meat is used as a popular replacement for American catfish. The taste is described as sweet and significantly milder than their catfish cousins. Swai is known to have a tougher texture and slightly blander taste than basa, another shark catfish that is found in the same region.

Swai meat is a good source of nutrition with plenty of protein and vitamin B12. Unless you live in Vietnam, you are most likely to find pangasius meat in the frozen section, where it can stay fresh and delicious for up to a year at a time. Frozen pangasius meat can be baked, broiled, or fried to achieve the best taste. Just remember to thaw your frozen fish out before you cook it to prevent too much moisture from entering the dish.

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