Although there are three species of electric catfish, the fish we see in the hobby is Malapterurus electricus.
Q. I have two, five-year-old electric catfish. Each fish is about 16 inches long and still growing. They each have their own 55-gallon aquarium. I consider them a very hardy species because they have survived many ignorant abuses on my part. They are my pride and joy. I would greatly appreciate any information on this freshwater fish species. I have been unable to find much information on my own.
A. Although I kept an electric catfish myself for several years, I realized after reading your letter how little I actually knew about these curious fish. I used mine to devour the fry of other fish that I was culling.
They are members of the African family Malapteruridae. Although there are three species of electric catfish, the fish we see in the hobby is Malapterurus electricus. It is said that they can grow to 3 feet in length and possibly 50 pounds in weight.
When offered for sale in pet shops (I believe they are illegal in Florida) they are usually about 3 inches long. They eagerly eat small feeder fish, worms and krill. I have a girlfriend with a pet electric cat, appropriately named "Sparky," who trained it to eat flake food when she first purchased it.
This is an important consideration for all potential purchasers of large predatory catfish. When the fish arrive in this country, they are hungry. This is the time to introduce them to prepared fish foods, unless you are ready to pay for ever-increasing amounts of feeder fish. These predatory catfish have never encountered a goldfish in the wild, but they are attracted to the movement of a possible food source.
Therefore, in a dimly lit aquarium that has a current of water produced by a powerhead or filter, if you sparingly feed krill, small pellets or flakes into this current, the movement will attract the catfish. They "learn" to accept these fish foods (remember, they're hungry). After they're accustomed to these foods, feeders can be used as a treat rather than being "the only thing they'll eat."
Back to the electric cats. Because you've been maintaining yours for five years, you realize how undemanding they actually are. Like most fish, they thrive in good water quality rather then a particular water chemistry. You are wise to maintain them in separate aquariums. Although I know of hobbyists who have kept one electric catfish in community aquariums of large catfish, I don't know of anyone (outside of public aquariums) who has kept two of them together successfully for any period of time. Obviously, they are capable of generating an electrical charge, which can be used for defense, stunning of prey or perhaps a method of communication — something like, "move now, this is my territory."
Nothing is really known about reproduction in electric cats. According to Breder and Rosen (1966. Modes of Reproduction in Fishes. T.F.H. Pub. Pp. 263-264.), "Efforts were made over long periods at the New York Aquarium to induce reproduction in this species. They were always unsuccessful and always resulted in the survival of only one fish after a period of a week." I guess this means that like with so many catfish families, we just don't know, yet, what the necessary trigger for spawning these fish is.
Enjoy your pets as the curiosity they are. I'm sure their lack of a dorsal fin only adds to their comical sausage-like appearance.