From the aquarist's perspective, they're identical to Ctenopoma fasciolatum. Peaceful, grow to about 8 cm long, eat anything wormy or small shrimpy. Suitable for a community tank.
Both species change their colours, and can be easily mixed up outside of breeding, and the females of both are probably indistinguishable. Supposedly, the markings on the males in breeding conditions are distinct: Ct. congicum has dark vertical bands on the flanks, while Ct. fasicolatum is lighter and has a wavy pattern of light and dark scales. I'm not convinced importers reliable distinguish the two species.
Nice fish. I kept my Ct. fasciolatum in a community tank with African tetras and Synodontis. Fed mostly on bloodworms. No aggression among the four individuals that I could discern.
If you can, get a hold of Jorg Vierke's "Bettas, Gouramis, and other Anabantoids". Very useful for keeping and identifying these oddball labyrinth fish.
Cheers,
Neale