If you’re looking for fun fish that will entertain, yet don’t require too much space, I highly recommend some Clown Killifish.
 
Hailing from western Africa and found in the countries of southern Guinea, Liberia, and Sierra Leone, Clown Killifish, scientific name Epiplatys annulatus, are peaceful micro-predators that feed mostly on tiny flying insects and invertebrates.
 
In their natural habitat, this tiny prey is abundant in the marshes, streams, swamps, and water holes that Clown Killies call home.