If you have a small fish and want to raise a big one.

Heterotis niloticus may be a good choice if you have small fish and want to raise large ones. It is the only one distributed in Africa. Its trade name is "African Black Dragon". It belongs to the same family as the famous giant hyoid in Brazil. Unlike other predatory arowana, the Nile isoauricular hyoid fish is filter-feeding and feeds on plankton in the water, while the small fish in the same tank are quite safe.
However, the disadvantage of the Nile heterotopic hyoid fish is that it is a little irritable. After getting out of the tank, several big fish in the tank were chased and jumped, while the small fish were completely unaffected.Microblog Video of Flash Perch