Catfish

Scaleless and heavily bewhiskered, catfish (order of Siluriformes) struggle to convey gracefulness. With nearly 3 000 species spread across continents – a pattern called “cosmopolitan distribution” – generalizations are tricky. But overall, these mostly (though not always) freshwater animals are clunkily big, with none of the swagger of other large fish such as tuna. The eyes are small, almost an afterthought: the food detection function is largely devolved to the mighty whiskers, technically known as barbels. These guide the fish through the semi-opaque depths where they tend to feed. Catfish lack the sizeable air-filled bladders that promote floating: theirs are comparatively tiny. Flat, bony heads further weigh the animals down.

What with all this rummaging, a “muddy” reputation clings to river catfish – even more so than to carp, a fairly close relative. When, in late 2021, engineers seeking to unblock a drainage pipe in the Austrian city of Linz brought to light a 2.5-metre, 100-kilogram specimen, the episode appeared to synthesize the creature’s least cuddly attributes: lumpy, drawn to murky habitats, a potential nuisance.

All true, no doubt, but also selective. Catfish, in fact, are probably more than averagely intelligent by fish standards. We may not know what they say to each other, but we do know that their communication system, both acoustic and olfactive, is quite developed: they are good at emitting signals of distress, for example, and good also – unlike some of us lot – at gauging the precise age, reproductive state and social status of prospective partners.

Catfish are cunning, innovative predators. In 2012, one study of Europe’s largest freshwater fish, the wels catfish (Silurus glanis), documented what appeared to be new “beaching” tactics by the animals in the river Tarn, in the French city of Albi. Lying in wait at the edge of the water, the catfish would leap onto land, in flash incursions, to snatch live pigeons. Such hunting ingenuity, akin to the amphibious dexterity of crocodiles, testifies to highly adaptive qualities. Warm water environments, particularly those that have been modified by humans, are especially congenial to catfish: they live long lives, up to 80 years, and reproduce abundantly – all of which means catfish are easily farmed, generally sustainable to eat, and pretty inexpensive. Consequently, they are common in the diets of Europe, Africa, Asia and the southern United States of America.

When it comes to cooking freshwater catfish, you can readily eliminate any muddiness by cutting out and discarding the darker central parts of the raw fillets, then soaking the fillet strips in lemony water. As you would with carp and other bottom-feeding fish, make sure all the blood has drained off. You’ll end up with flesh that is mild-flavoured and moist, loaded with lean protein and rich in vitamins D and B12: both are vital nutrients and frequently missing from diets.