The Clown Knifefish is one of the true monster fishes that are available in the aquatic hobby. The cute little ones that are sold at your local fish store at 4” to 5” will very quickly grow, and grow, and grow, and eventually you will have a 24” fish on your hands.
Therefore, if you want to keep the clown knifefish please be prepared for what you will have to do as it outgrows tank after tank. The basic body color of the clown knifefish is a very attractive slate gray, with a nice sheen to the entire dorsal side of the fish. Small fish have a few black circles with a white border, and as the fish matures the number and size of these circles increases.
The body is a knife shape, with the anal fin running the entire length of the fish and always rippling lightly. With the anal fin, a shake of the body, and the use of strong pectoral fins, the clown knifefish is a perfect ambush predator. Feeding usually requires live foods to get started, and then if the tank conditions are to the fish’s liking, and you are a patient hobbyist, they can be switched over to solid frozen fish, prawns and the like.
The clown knifefish is by nature a nocturnal fish, and it will be most happy if the tank does not have bright light and if there is a nice cave, driftwood or other place for the fish to hide during the day. The tank should also be heavily planted, and have a portion of the tank shaded with floating plants.
They will do fine in groups, as long as the tank is large enough and there are enough hiding places for each clown knifefish. They get along fine with other large peaceful fish, but they can and will eat anything that they can fit into their very large mouth. There are no records of the Clown Knifefish breeding for hobbyists that I know of.