A much maligned aquarium fish is proving a big hit in the supermarkets, as customers switch from expensive local varieties to cheaper imports.
Sold under the name of "Vietnamese river cobbler", the Iridescent shark catfish, Pangasius hypophthalmus, is apparently outselling more popular species of fish from our local waters.
According to a report from The Telegraph, Pangasius has grown in popularity at Tesco by around 60% in the last few months, without even an advertising campaign.
Tesco introduced the species to its wet fish counters in 2007 and it now sells twice as much as Rainbow trout.
These 60cm/24" Pangasius are half-grown and are held in one of the UK's largest private aquariums.
Pangasius hypophthalmus, which can reach 120cm in length and weigh over 40kg, is found in the Mekong and Chao Phraya basins of south east Asia and is a popular food fish locally.
The species is closely related to the Giant Mekong catfish, Pangasius gigas, which can reach over 3m/10' in length, and the related Pangasius sanitwongsei, which grows almost as large. (See Nine foot Giant pangasius catfish caught).
It is farmed on a massive scale for the food trade, and is said to be one of the most economically important aquaculture species in Thailand. Excess specimens are sold cheaply by aquarium exporters, however, they are entirely unsuitable for aquariums.
Aquarium suitabilityThe species was once a common sight in aquarium shops, but is now considered unsuitable for the home aquarium and stocking the species is frowned upon by experts.
Pangasius hypophthalmus can reach several feet in length and lives in large, fast-flowing rivers in large shoals.
It's an active and fast-moving fish that requires more space than even the average public aquarium is capable of providing.
In captivity, it tends to rapidly outgrow aquariums and often physically damages its head and eyes by accidentally swimming into the aquarium glass.