Small, wriggly and shy, the tiny loaches of Pangio still have an almost cult-like following. Here are some you will and some you probably won’t see in stores.

WORDS: NATHAN HILL

Every Pangio’s markings can be as unique as a fingerprint.

All Pangio are highly sociable and need to be in groups.

WHEN IS a kuhli loach not a kuhli loach? When it’s in a British aquarium, usually. Like the worst of hangovers, the name is hard to shake off, but it’s likely that the true kuhli loach — named after the collector Heinrich Kuhl — has not once been exported from its home in Java. You might even see the fish listed as a ‘coolie’ loach, a name we’d be better off doing away with altogether — coolie is an outdated pejorative term for unskilled Chinese or Indian labourers. How about we just run with ‘eel loaches’ instead?

Eel loaches are simultaneously some of the most enjoyable fish to watch, while also being some of the most difficult fish to spot. For the best part — but not exclusively — they inhabit bodies of water with dense overhead canopies, low light levels, and more cover than they know what to do with. That’s quite the opposite of most modern aquaria, with their high output lights, minimalist layouts and pristine water. These are fish that are perfect for those who love their tankwater the colour of autumnal leaves. For those that prefer things bright and barren, eel loaches will simply go into hiding, never to emerge again.

Every Pangio is like a fingerprint, with individual markings, and that’s something that makes species identification difficult. Worse still, many of their markings shift and twist with age, making an accurate diagnosis all the trickier. The images here are largely a guide, but cannot hope to account for all the individual variations in each species.

Eel loaches belong to the Pangio genus, and you’d be forgiven for thinking that this genus contained only the one species. Commercially, Pangio semicincta makes up the majority of imports, and that’s the one you’re likely to have already met on your travels (even if it will have been sold as a kuhli/coolie loach).