If your thing is smaller, brighter fish, or if you’ve been a lifelong tetra fan, then Cherry barbs (Puntius titteya) will seek a place in your set-up. If you prefer your fish to be more boisterous, ...

Puntius barbs have so many good qualities that there's a species in the genus for every fishkeeper, as Dr Heok Hee Ng explains. A popular notion of an aquarium is a glass box with fish in midwater.