Swai Fish vs. Channel Catfish: 3 Key Differences Explained

Catfish (order Siluriformes or Nematognathi) can live in fresh, saline, and brackish water. More than 3,000 different species of catfish are commonly found in lakes, ponds, reservoirs, and moving bodies of water. Catfish, along with carp, tilapia, and salmon, are among the most commercially farmed types of fish. In the United States, catfish are a major part of the aquaculture industry, 90 percent of which are channel catfish (Ictalurus punctatus). Another species of catfish, the basa (Pangasius bocourti), is among the most farmed fish globally, particularly in Southeast Asian countries such as Vietnam. Basa meat is called swai, and, similar to channel catfish meat, it is an affordable protein option. Continue reading to learn the major differences between these two important food fish.

Appearance and Characteristics

Basa fish are members of the shark catfish family (Pangasiidae). These freshwater fish are native to the Mekong and Chao Phraya river basins. They typically measure up to 47 inches long and weigh 4.4 to 19.8 pounds. Wild basa fish have been recorded to measure 5 to 8 feet long and weigh over 200 pounds, with the heaviest being a 650-pound basa caught in Thailand. However, individual commercial swai fillets usually weigh 0.5 to 0.75 pounds because farmed basa are harvested once they weigh 2.2 to 3.3 pounds. Basa fish have rounded heads that are broader than their bodies. Their dorsal side is dark blue, grey, or brown, and their ventral side is much lighter, almost white.

Channel catfish are members of the North American catfish family Ictaluridae. Channel cats are native to North America, but have been introduced throughout South America, Europe, and Asia, where many countries consider the species invasive. On average, channel catfish measure 12 to 20 inches long and weigh 2 to 4 pounds. The largest caught channel cat specimens have measured up to 4.3 feet long and have weighed up to 58 pounds. In aquaculture, channel catfish are harvested once they weigh 2 to 3 pounds, and sometimes are harvested at 1.5 pounds. Channel catfish fillets can range from 3 ounces to 11 ounces.

What do Basa Fish and Channel Catfish Eat?

Basa fish are omnivores; they eat small marine critters and bits of plants. Their diet consists of small fish, brine shrimps, and bloodworms. In captivity, they are often fed crickets. Because they are bottom feeders, basa fish are typically found in large, deep bodies of water. 

Channel catfish have taste buds all over their bodies; therefore, they can taste their prey from a distance. These catfish feed by using their mouths to create a vacuum that sucks in prey, which they then swallow whole. They prey on yellow perch, sunfish, snails, clams, crayfish, snakes, frogs, and insects, and they will also eat nuts, algae, seeds, and grains.

Commerciality

Most swai farms are located in Vietnam, which is by far the world’s largest producer and exporter. Other countries with notable swai farming include Thailand and Cambodia. In the early 2000s, Vietnam exported large quantities of basa and iridescent shark catfish (Pangasianodon hypophthalmus) to the United States. In response, the US catfish industry lobbied for stricter regulations. This resulted in a law being passed in 2003, making it illegal to sell any species that does not belong to the Ictaluridae family under the name catfish, and anti-dumping tariffs were imposed on imported swai from Vietnam.

Channel catfish also make up a large part of the aquaculture industry, especially in the Southern United States. Just four statesstates—Mississippi, Alabama, Arkansas, and Texas—account for 95 to 97 percent of farm-raised catfish production in the United States. Channel catfish are becoming increasingly popular for research. Scientists are using cloned channel catfish cells to study the species’ immune system to develop disease-resistant and fast-growing fish for aquaculture.