That Fish Blog – Aquarium Advice and Information
Hello, Frank Indiviglio here. It takes some doing to stand out among the catfishes, a group that contains some of the most bizarre creatures on earth. Yet the Electric Catfish (Malapterurus electricus) does this quite admirably. Indeed, this species is so unique that it and the small mouth electric catfish (M. macrostoma) are alone classified in the family Malapteruridae.
Characteristics and Cautions
The Electric Catfish has a number of qualities that would seem to mitigate against its popularity, but catfish enthusiasts, myself included, seem drawn to “unlovable” beasts. It is no beauty, and is impossible to house with any species other than its own – tank mates that are not shocked to death are eaten! Fortunately, it is 
immune to its own unique defense system.
In all seriousness, however, this fish is not for beginners. It may reach 3 feet in length, and when disturbed emits electrical charges that are, at 400 volts, strong enough to stun adults (the strength of its charges increases with size, but even a 3 inch specimen can make itself felt). Obviously, it is imperative that children and mentally challenged persons be kept away from electric catfishes.
Natural History
The Electric Catfish inhabits slower-moving portions of the Nile, Niger and other river systems in Central and West Africa. The small mouth Electric Catfish is confined to the Congo River Basin and rarely appears in the pet trade.
This species captures its prey, mainly other fishes, by releasing short bursts of electricity. Electrical impulses are also used for defense, but do not assist in navigation (as is the case for the knife fishes). A unique pectoral muscle that surrounds most of the body generates the electrical discharges.
Pairs form during the breeding season, and the eggs are laid in a self dug or confiscated hole below a sunken log or rock. Little else is known of its reproductive behavior.
Captive Care
Despite, or perhaps because of, their formidable defenses, electric catfishes make most responsive pets. Owners invariably describe them as alert and quick to respond to one’s presence (in such cases, feed but don’t “pet” them!). They soon abandon their nocturnal ways where food is involved.
Plan for a large, well-covered tank, as these stout fishes may reach 35 inches in length. They seem to be fish specialists, but will also take all manner of other meaty foods, carnivore pellets, prawn, earthworms, insects, crayfishes and just about any other small animal. Long term captives rarely discharge electricity during routine tank maintenance, but they should none-the-less be treated with respect and caution.
Captives do best under low light and in moderately soft water at 76-78 F and 6.5-7.5 in pH. A suitably powerful filtration system is essential, as are regular water changes. Electric catfishes prefer sluggish waters in the wild, and do not abide strong currents in captivity. Albinos are sometimes available.
Research Potential
The Electric Catfish is yet another relatively common, hardy fish about which we know very little. Documenting their breeding behavior would be a most interesting and useful endeavor…please consider it if your resources allow.
A New Exhibit
I recently obtained a nice group of Electric Catfishes and helped set up an exhibit for them in the new African Underwater Adventure display at the Maritime Aquariumin Norwalk, Ct. Please visit if you have a chance.
Further Reading
You can read more about the Electric Catfish at Fishbase.
Please write in with your questions and comments.
Thanks, until next time,
Frank Indiviglio
I have heard that the electric catfish can be housed with synodontis cats, not sure if this is true. It would be nice to have a tankmate in there with him!
I wouldn’t recommend it…they tend to be territorial and they’re predatory. As they outgrow the synos, the synos might become a meal, and since synos are more active than these guys they may agitate the electric cat and end up stunned. It would have to be a very large tank with ample ornamentation and hiding spots if you insist on trying it, so at least they may have enough space as to avoid each other.
Appreciate it, E-Cats are interesting enough on their own to be worth a whole aquarium to themselves anyway. Very personable for a catfish. I am normally a marine enthusiast, but this guy is among my favorite fish.
Dear Frank,
We have two very shy catfish (about 6-7cm long) that spend most of their time hiding behind a wooden feature in our home fish tank. We recently added 19 small fish to the tank that my mother received for her birthday. Over time, some of the fish have gone missing. We are now left with 9 smaller fish. Could it be that the catfish are snacking on the small fish once they pass away?
Artie Torrible
Hello Artie, Frank Indiviglio here.
Thanks for your interest in our blog.
You’re very lucky to have a fish-keeping Mom; I had the same. An American Eel that I presented to her as a gift lived for 19 years (and ate all her other fish!).
It is very likely that the catfishes are eating the others, but I would be able to be more certain if I knew what type of catfish you have. When you have time, please write back with the name if you know it, or perhaps send a link to a photo on the net.
Catfishes can be tricky – many hide by day, just as you describe, but become real “terrors” at night, catching and eating surprisingly large fishes. You might want to check if your local store carries a night-viewing bulb similar to this one…these allow you to observe your fishes nighttime activities (some will still go about their business when lit by a flashlight also).
Dear Frank,
I recently got an electric catfish, it’s all set up in my tank and jm working on making more hideouts. But I was wondering how often do they eat?
Hi Jbean, Frank is no longer with our blog but I would be happy to help you out. Once daily feedings are fine for these fish. Keep in mind that they are nocturnal so feeding them at night or just before or after the lights go out is best.
Nopain1984@comcast.net, I have a 31 inch electric cat 3 yrs old,looking for a bigger home has outgrown his 220 tank,any contacts would help,thanks,Erich Kronenwett
Hi Erich, We sell larger tanks in our Lancaster, PA retail store but without knowing where you are located, it is difficult to make recommendations to you. Not many companies ship larger tanks due to the high shippign costs and risk to the tank itself. If you aren’t near our store, I would recommend checking with your local fish stores for recommendations on where to get larger tanks in your area.
I like catfish
Gihan buddhika,
Hey, I am from Sri lanka. I also have a pair of electric catfish. I need know how to breed them, and how we can find male & female. If anyone knows that please write it down.
Thanks
Hi Gihan, To my knowledge, Electric Catfish have never been reported to breed in captivity. Sexing them is also extremely difficult and not reliable; male are thought to be more slender than females. We wouldn’t have any resources on where to get Electric Catfish in Sri Lanka. I would recommend asking local fish stores or aquarium clubs that supply to your area.
Have electric catfish Aprox 6” lives in community tank with blue rams, puffers, red tail sharks,barbs,Gouramis, & a lobster & is no problem