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Related FAQs:  Electric Catfish, Electrogenic Fishes, Catfish: Identification, Behavior, Compatibility, Selection, Systems, Feeding, Disease, Reproduction

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/A Diversity of Aquatic Life

The Electric Catfishes, Family Malapteruridae

By Bob Fenner

Malapterurus electricus juvenile

    Oh, how times change! When I was a young pet-fish beginner back in the early sixties, there was but one accepted species of electric catfish... currently (pun not intended) there are eleven! All joined in the same genus, Malapterurus, and spread widely about Africa's freshwaters, with the "star" species M. electricus being found from the Nile to the Zambezi and much of central Africa. This species and humans have been acquainted since ancient times, with clear identification being made by Egyptians in hieroglyphs more than five thousand years ago.

    Electric cats are unmistakable at the family level. They are flabby bodied (the scientific name is derived from the Greek: mala = soft + pteron = fin + oura = tail), lack a dorsal fin and have an adipose fin well to the rear but separate from the caudal... oh, and are not only revoltingly homely, but voltingly shocking!


    These cats are very sedentary, spending almost all their time reposed on the bottom. Think about it... if you could generate 300-400 volts wouldn't you wait till your food came on by and just zap it? The principal species available is a large animal, and it can grow quickly if fed regularly... this coupled with its shocking behavior calls for large quarters (so you don't have to move it). There are folks who keep electric cats in systems of only a few tens of gallons... but you are advised to dedicate one of a few hundred if thinking of keeping M. electricus in the long term. Electrical discharges function for both prey seizure and defense (not for communication or navigation as in some more weakly electrogenic fish families)... thus a word to the would-be aquarist who considers these fishes.

    Water quality is not particularly important. Species kept do fine at a pH between 6 and 8, though neutral water of moderate hardness is preferred. Temperature should be tropical, somewhere twixt 20 and 26 C.

    Electric cats prefer dusk-like settings, so either low-light or good plant cover is advised. They are secretive by nature, especially on first introduction, so a ready-made cave of some sort should be supplied. Take care however in arranging large, heavy objects in their system as these cats are both prodigious diggers and pushers of materials... and your specimen may well be crushed if massive aquascaping falls on it.

    Due to their digging behavior and eating habits, undergravel filters are useless with these fishes, and you should instead utilize outside power filtration (hang-on, canister, wet-dry...) instead.


    In the wild these fishes eat an assortment of small/er fishes and crustaceans. Other tankmates will always be at risk of electrocution. It has been done (e.g. with larger cichlids), but most keepers of electric cats keep them to themselves... in dedicated biotopic settings. Though they can be kept more than one to a tank as juveniles, electric catfishes become quarrelsome with growth and are best maintained solitarily. Not to worry re this fish becoming lonely, as they imprint on their keepers readily, becoming quite the household pet, actually rarely shocking their owners.

Species Aquarists Are Likely To See (and feel!):

    Though other species at times make their way into pet-fish markets, the almost-exclusive staple is M. electricus.

Malapterurus electricus (Gmelin 1789), the Electric Catfish. Africa: Nile and tropical Africa (except Lake Victoria and rivers of East Africa north of the Zambezi), Lake Tanganyika and throughout the Congo system. To 1.2 meter in length (more than four feet!). Natural water cond.s: pH 7-8, dH to 20, temp. 23-30 C.


Malapterurus microstoma Polle & Gosse 1967, the Smallmouth Electric Catfish. Africa: Congo basin; mainstream and large tributaries. To 69 cm. An occasional aquarium import.



    Electric cats eagerly take all types of foods... in fact, too eagerly, and one must be self-controlled lest their malapterurid turn into a living blimp or worse, a dead one. Sinking meaty or prepared foods of high protein are appreciated, daily for smaller specimens, a few times weekly for larger ones. Be aware that your fish will keep eating about as long as you're willing to stuff it, but that this is not good for electric cats. They will live much longer, healthier lives being occasionally fasted. In the wild these fishes are active, well, more active at night, but at the sizes they are typically imported (2-6 inches) are easy to train to take food during the day.


    Tough otherwise, malapterurids often fall prey to simple white-spot or ich infestations... or likely more frequently, from medications used to treat such ailments. As naked catfishes they are easily susceptible to poisoning from Malachite Green, a common ingredient in ich remedies. If using these, take care to apply half doses, elevate temperature (to mid to upper eighties F.) or rely on other non-dye or metallic med.s.


    Electric cats have been observed reproducing in the wild. This occurs between pairs in the summer in holes they dig in river banks. Some accounts describe some species as mouthbrooders. Males are decidedly slimmer than the very round and heavy-set females.

About Their Shocking Behavior:

    Even small specimens of malapterurids can render a noticeable electrical jolt, with larger specimens scaling up the possible voltage. Such events can be painful indeed, and you are warned to make provision for avoiding shocks if you keep these fishes. Standing on insulators, using rubber gloves and non-conductive handled tools like nets, gravel vacuums and algae scrapers... Best to work on these fishes tanks once they are fully awake and aware of your presence, ahead of sticking ones hands in their water.

    If you delve into fish physiology you will note that malapterurids generate their electrical potential from dermal structure, as opposed to internal organs like most other electrogenic fishes, formed of muscle just below the skin.


    Obviously this family of catfishes is not for many aquarists. However, given a large, dedicated system and regular care, one can have a real "aqua dog" pet for a few decades in an electric cat.

Bibliography/Further Reading:

Catfishes on the Internet: http://phylogeny.arizona.edu/tree/eukaryotes/animals/chordata/actinopterygii/siluriformes/siluriformes.html

Planet Catfish: http://www.planetcatfish.com/core/index.htm

Burgess, Warren E. 1989. An Atlas of Freshwater and Marine Catfishes. Tropical Fish Hobbyist Publications. NJ, USA. pp. 786.

Jackson, Lee. 1990. Electric catfish. FAMA 3/90.

Krechmer, Michael. 1995. Current events with the electric catfish. TFH 7/95.

Nelson, Joseph S. 1994. Fishes of the World, 3d ed.. John Wiley & Sons, Inc. NY. 600pp.

Speice, Paul. 1993. The tickle fish and other shocking stories. FAMA 2/93.

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