Kannume's a nice mormyrid; pretty rare species, too. Most of the "kannume" that I've seen are just longirostris.
They're odd, temperamental things; very active, very prone to harassing and chasing tankmates if able. A lot of East Asian keepers keep them in solo, bare tanks with some PVC pipes and toys like balls.
Very difficult to feed- they have small mouths, very high metabolisms, and eat somewhat slowly. Becomes a progressively larger issue as the fish grows. They'll typically accept f/t tubifex and bloodworm, but prefer live black worms. They won't usually accept pellets or flakes. They grow pretty slow in captivity, likely due to insufficient dietary provision. Tank size would ideally be something like a 300G for a single 30cm juvenile. Most say they aren't worth keeping because of their difficulty of maintenance.