Ummm.....barb.....asia!!! Der!! I don't think they are with Hippos, isn't it a different type of barb? Might be TF's though....lol.....
They are found in Southeast Asia; Thailand, Malayan Peninsula, Sumatra, and Borneo. They inhabit large waterways; rivers, streams, canals, ditches and will enter flooded fields.
There are also a lot of african characins that you don't see in the hobby too often but reach decent sizes. Also, Mbuna and related cichlids are from the rift lakes, which I don't believe are inhabitied by hippos. Could be wrong, but hippos are mostly riverine.
Yes tinfoils are asian not african.
The fish you see in the films of hippos are mainly various Labeos such as african carp (Labeo coubie), as well as several others. Some feed on dead skin and parasites but most feed on the droppings, either directly or onthe algae and organisims that the dung nourishes. There is a set of clear water springs in Kenya that supports at least a dozen species of fish that specialize in hippo dung. Can't remember the name of the springs offhand.