Striped catfish (Pangasius hypophthalmus)
Pangasius are a very large and wide ranging family of shark catfish native to rivers in Asia. The striped catfish, Pangasianodon hypophthalmus (also known as “tra” in Vietnam and mostly still named Pangasius hypophthalmus) has been cultured for decades in Thailand, as it is a very hardy, fast-growing fish that is able to consume a wide variety of poor quality and low protein feeds. The fish achieves 2 kg within a year (from 0.5g) and is very tolerant of poor water quality and low dissolved oxygen levels (is a facultative air breather, so no aeration necessary).
They grow to over 10 kg and have been known to grow to 40 kg maximum size. The fish is happy eating a wide range of food and is often raised on manures or waste feedstuffs. The flesh of the fish tends to be pigmented yellow or orange due to the fish storing pigments from its diet (like salmon) and is high in lipid. Flesh quality can be controlled to a large extent by using selected feeds and low protein feed has been shown to reduce fat content and increase the shelf life of the meat.
In Thailand striped catfish have been typically been grown under chicken houses, often in polyculture with Clarias catfish. As such it has historically been considered a cheap and poor quality fish. This image began to change when Vietnam began culturing the species on a vast scale for export. By culturing the fish at high density in ponds with water exchange and using special formulated feeds, farmers were able to produce fish with white flesh and very good flavor.
Within the last 10-20 years, the striped catfish has become popular with consumers in the US as a cheap alternative to locally farmed channel catfish. The U.S. government, in attempt to remove the threat to local catfish farmers, imposed anti-dumping duties in 2003. Despite the high import duty charged, Pangasius are now in the top 10 list of most popular seafood species consumed in the US. This trend is now also becoming worldwide, as the EU, Russia and many other countries import the product from Vietnam. Culture has now spread to Bangladesh, India, Nepal and many other countries outside the geographic range of this species. It is very suitable for poor, developing countries, as the fish can be raised at high density, without aeration, using a wide variety of poor quality feeds and can be transported live in only small amounts of water. For this reason it can be kept fresh, without ice, in hot tropical countries for long periods of time.
There are other species of Pangasius catfish that are less popular as culture species including Pangasius bocourti (“basa” catfish in Vietnam), Pangasianodon gigas (giant Mekong catfish) that can grow to over 200 kg, Pangasius sanitwongsei (Chao Phraya catifish) that grows to over 100 kg and Pangasius larnaudii (spot pangasius). There has also been work on producing hybrid species in Thailand in order to get a hardy, fast-growing fish that doesn’t store pigments in the meat, since white flesh is in most demand. Nam Sai has also worked with various species, but at present is still concentrating on producing pure striped catfish which are hardy and exhibit good growth performance.
Unlike tilapia which spawn all year round, striped catfish can only be spawned from April to October and fry are generally available from the end of April up until December. Please allow 2-3 weeks for delivery of striped catfish.
|Number purchased||Price in Thai baht||Price in US$ per 100|
|The prices do not include packing and transport costs. Minimum size of order = 2,000 fish|
|Baht/$US = 30|
All striped catfish are exported at a size of 0.5g. They are twice the size of 1” tilapia and so the stocking density per box is reduced proportionately:
|Destination||Total transport time (hours)||Fish packed per box|
|Thailand||6 to 10||1,800|
|Asia, close by||10 to 15||1,000|
|Asia, far||15 to 20||800|
|Middle East||15 to 20||800|
|Africa||30 – 45||400|
|U.S.A.||35 – 45||400|
Nam Sai uses anesthetic to sedate striped catfish during transport, as, unlike tilapia, reducing temperature does not improve survival. Packing costs are charged at the same rate as for tilapia.