Shadow catfish

A species that isn’t celebrated enough in the public mindset is the Shadow catfish, sometimes still imported and offered under the wholly incorrect name of Pelteobagrus ornatus (though decreasingly so). A truly miniature cat, measuring just shy of 4.5cm, their out and about antics and bold swimming style evokes thoughts of Pangasius catfish — giant cats ill-suited to domestic life (and actually farmed as a food fish). While Anchor catfish like to lurk between rocks, and Oil catfish like to wedge themselves into wood, the Shadow catfish is one fish here that will always be in your face. While Shadow cats are superb for an Asian biotope, alongside Pangio and Rasbora species and with diffuse lighting and plenty of vegetation, their peaceful disposition means that they can go well in any suitably acidic aquarium where they’ll not be bullied. Acid conditions do seem to be a must, though, with owners reporting mucous issues (sloughing and sliminess) and loss of condition if kept too far above neutral.

It’s more than possible to sex them, though you’ll need to get up close. Males have a long genital papilla right at the front of the anal (unpaired underside) fin, and they are leaner too. Females are slightly chunkier, but the real giveaway is the green tinge they develop at their ovaries when they start to develop their eggs.

Oh, and the other thing to avoid is flow. Although they may look hydrodynamic and built for speed, in the wild they prefer to live under thick mats of plants with no notable water movement. That makes them ideal contenders for a tank with an air driven filter, but truly awful for a Hillstream loach layout. In fact, excess flow may be one of the reasons that some of these fish struggle to retain body mass, even when eating readily.

If you love Pangasius but don’t have an indoor pond to hand, these are the fish for you.