African Electric Catfish

Electric catfish were known to the ancient Egyptians, being unmistakably depicted in bas-reliefs in tombs more than 5,000 years old. The ancient Egyptians called electric catfish "he who had saved many in the sea", presumably because any electric catfish caught together with other fish would shock the fisherman through contact with the wet boating pole or the net, causing him to let go of his net and liberate his catch.

Preliminary data suggest that what is currently considered M. electricus consists of at least nine species (of which four miniature species with highly reduced electric organs from Zaïre possibly belong to a separate, undescribed genus) (Moller, 1995).

The phylogenetic relationships of the Malapteruridae are unclear. Howes (1985) proposed that they are most closely related to the Old World catfish family Siluridae, but Bornbusch (1991) questions this argument.

Malapterurus species have been reported to hiss like cats by Sorensen (1894), but this claim has never been substantiated.

Below is a list of additional resources on the web concerning the electric catfish:

For more scientific information on the electric catfish, visit the a href=" http://www.fishbase.org/Summary/SpeciesSummary.cfm?genusname=Malapterurus&speciesname=electricus">FishBase

For a picture of the electric catfish on an ancient Egyptian bas relief, click a href=" http://people.clemson.edu/~jwfoltz/WFB300/subjects/Ostario/catfish/Egyptian/egyptian.htm">here

Species in the genus Malapterurus have a general body form that has often been described as a bloated sausage. When they swim, their soft, puffy bodies give tham the "appearance of a rather rigid sausage propelled by somewhat ostraciform movements" (Lissmann, 1958).

The body is elongate and cylindrical, and the head is slightly depressed. The eyes are small, the lips are rather thick, and the snout is rounded with widely separated nostrils. The gill openings are narrow and restricted to the sides. Malapterurus species have three pairs of barbels, and lack a dorsal fin. The pectoral, pelvic and caudal fins are rounded. The pectoral fins lack spines and have 8 to 9 fin rays. The pelvic fins have 6 fin rays and are inserted approximately halfway between the tip of he snout and the base of the caudal peduncle. The anal fin has 9 to 10 rays and is located anterior to the adipose fin, which is low and has a rounded posterior edge.

Malapterurus electricus can reach up to 1220 mm in total length (Skelton, 1993).

Species in Malapterurus are generally grayish-brown on the back and sides, fading to an off white or cream color on the ventral surfaces of the head and body. There are irregular black spots or blotches randomly distributed on the sides of the body. The posterior half of the caudal peduncle usually has a dark brown or black vertical bar and a cream vertical bar immediately anterior to it. The distal margins of the anal and caudal fins have a cream margin, and the base of the caudal fin has a cream region and a dark brown crescentic band immediately posterior to it.

The three different species of Malapterurus can be differentiated by the following key (after Sagua, 1987):

1a. Gill rakers on proximal two-thirds of first ceratobranchial, usually not exceeding 15; adipose fin short, sloped posteriorly M. minjiriya

1b. Gill rakers throughout entire length of first ceratobranchial, usually 15 to 23; adipose fin rounded, see 2a and 2b below.

2a. Mouth relatively narrow; snout relatively long M. microstoma

2b. Mouth relatively wide; snout relatively short, M. electricus

The most notable aspect of Malapterurus is its strong electrogenic ability. The electric organ, which is evolved from its pectoral muscle (Johnels, 1957), surrounds the body over most of the length of the fish and is capable of discharging up to 350 V (in a 500 mm fish; Keynes, 1957).

Range mass: 0 to 20000 g.

Range length: 1220 (high) mm.

Other Physical Features: bilateral symmetry

Average lifespan
Status: captivity: 10 years.

Species in the genus Malapterurus are generally found among rocks or roots in turbid and/or black waters with low visibility; they favor sluggish or standing water.

Habitat Regions: freshwater

Aquatic Biomes: lakes and ponds; rivers and streams

The genus Malapterurus is found throughout western and central tropical Africa and the Nile River. They occur in all major freshwater systems including the Buzi Niger, Ogooué, Omo, Sanaga, Sabi-Lundi, Senegal, Shari, Zaïre and Zambezi River basins,as well as Lakes Albert, Chad, Kainji, Tanganyika and Turkana.

There are currently three species of Malapterurus. It is believed that M. electricus is restricted to the Nile River and Lake Chad (Moller, 1995).

Malapterurus minjiriya is known from the Niger River and Lake Kainji and M. microstoma is known from the Zaïre River basin.

Biogeographic Regions: ethiopian (Native )

Malapterurus electricus is a voracious piscivore (Sagua, 1979; Olatunde, 1984), hunting and stunning its prey using its paralyzing electrical organ discharge (EOD). It is an opportunistic feeder and will feed on the most readily available prey within its habitat. Electric catfish are able to consume prey up to half their size (Sagua,1979). The presence of high percentages of electric catfish with empty stomachs in wild-caught specimens studied suggests that these fish are slow-moving, deliberate feeders with infrequent, heavy meals (Sagua, 1979).

The EOD volleys involved in predation are long-lasting (up to 30 seconds long) and may comprise several hundred EODs. These feeding volleys are often preceded by low frequency "pre-volley" activity, which is believed to startle potential prey (Belbenoit et al., 1979).

Animal Foods: fish

Primary Diet: carnivore (Piscivore )

Malapterurus electricus is eaten as food in parts of Africa. Along the shores of Lake Kainji, smoked electric catfish is a popular delicacy (Moller, 1995). Besides being a food fish, M. electricus is also occasionally encountered in the pet trade as an aquarium fish.

The electric organs of Malapterurus have been used in studies of neuronal metabolism, axonal transport, and transmitter release (e.g. Volknandt & Zimmermann, 1986), being particularly suited for this task because of their innervation by only one giant neuron (Janetzko et al., 1987).

Positive Impacts: pet trade ; food ; research and education

Aside from giving an unpleasant surprise to the occasional careless fisherman who handles it (the EOD an electric catfish generates is not known to be fatal to humans), there are no other known negative effects of M. electricus on humans.

Negative Impacts: injures humans

Malapterurus is not considered to be threatened in any way by the IUCN and CITES.

According to Belbenoit et al. (1979) and Balon & Coche (1974), Malapterurus occur in relatively high densities (each fish is separated from its neighbor by 10 to 12 m). In Lake Tanganyika, Malapterurus occur in even higher densities, with fish separated by only 2 to 3 m (Brichard, 1978). These high densities could be due to the fact that, humans excluded, electric catfish have few natural predators (except for tigerfish).

However, the fact that the taxonomy of Malapterurus is poorly known and the discovery that some of the undescribed species currently lumped in M. electricus are endemic to small parts of Africa (Moller, 1995) means that continued deforestation could adversely affect the populations of these endemic species.

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

Perception Channels: tactile ; chemical

Nothing much is known of the reproductive biology of M. electricus According to Polle & Gosse (1969), breeding pairs nest in holes some 3 meters in length excavated in clay banks in water 1 to 3 meters deep.

Key Reproductive Features: sexual ; fertilization (External )

There are 141 species of fish recorded in the Senegal River, most of which are native; however, there are no endemic species of fish in the Senegal Basin. Among the larger native benthopelagic taxa are: the 170 centimetre (cm) North African Catfish (Clarias gariepinus), the 149 cm Electric Catfish (Malapterurus electricus), and the 92 cm African Carp (Labeo coubie).

Some of the larger native demersal fishes of the Senegal Basin are: the 204 cm Aba (Gymnarchus niloticus). the 200 cm Nile Perch (Lates niloticus), the 183 cm Sampa (Heterobranchus longifilis), and the 150 cm Cornish Jack (Mormyrops anguilloides).

Pelagic native fishes in the Senegal River include the 65 cm True Big-scale Tetra (Brycinus macrolepidotus) and the 16 cm Ansorge Fangtooth Pellonuline (Odaxothrissa ansorgii).

Diagnosis: tooth patches narrow; pectoral fin placed near body mid-depth; 7-8 branched caudal fin rays (Ref. 44050). 9-11 anal-fin rays, usually 10-11; 38-41 total vertebrae, usually 39-41 (Ref. 57130). Caudal saddle and bar pattern not present in adults (Ref. 57130), poorly developed in all ages (Ref. 44050). Flank and dorsum in adults and young marked with large blotches (some up to 4-5 times eye diameter); caudal fin of adults generally same color as flank ground color or slightly darker, larger specimens usually with spots or blotches in caudal fin (Ref. 44050, 57130).Description: body fusiform (Ref. 57130). Head deep and cylindrical; lower jaw only slightly prominent; 16-18 abdominal and 21-24 caudal vertebrae; 19 caudal fin rays (arrangement: ii-7-8-ii) (Ref. 44050, 57130).Coloration: dorsum tan or occasionally light grey; venter light tan; body bicolored but without sharp demarcation between dorsal and ventral shades; dorsum and flank marked with scattered spots and larger blotches, some as large as 4-5 times an eye diameter; blotching typically denser posteriad, where blotches may merge or overlap; venter usually unmarked, or with a few small spots; small spots usually present on paired fins of specimens larger than 15cm SL; caudal and anal fins well marked with small spots, plus some larger blotches on the caudal fin, in specimens of 15cm SL and larger; caudal fin bears a dusky bar with a pale basal crescent and a clear distal margin; dusky bar is narrow in juveniles and much broader in adults; pale basal crescent may be poorly developed in large adults, with the entire fin pigmented in the flank ground shade; caudal saddle and bar faint in juveniles, with the pale interspace matching the ground color; juveniles show a bar at the caudal fin base, and a less distinct saddle, extending ventrad to the body mid-depth; saddle has disappeared by 10cm SL, caudal bar may persist (faintly) in specimens up to 15cm SL; tiny juveniles (10-20m SL) are largely unpigmented (Ref. 44050).

Occurs among rocks or roots; favors sluggish or standing water. Active at night, feeding mainly on fish stunned by electric shocks. Forms pairs and breeds in excavated cavities or holes.

Dorsal spines (total): 0; Dorsal soft rays (total): - 0; Anal spines: 0; Analsoft rays: 9 - 11; Vertebrae: 38 - 41

Potamodromous. Migrating within streams, migratory in rivers, e.g. Saliminus, Moxostoma, Labeo. Migrations should be cyclical and predictable and cover more than 100 km.

It is assumed that the male tends the clutch. Others report that the male takes the eggs into his mouth. It is also unknown how the fry is immune to the electric shocks by the parents (Ref. 1672).

Echinostomum Disease. Parasitic infestations (protozoa, worms, etc.)

Neoechinorhynchus Disease. Parasitic infestations (protozoa, worms, etc.)

Clinostomum Infestation (metacercaria). Parasitic infestations (protozoa, worms, etc.)

Occur among rocks or roots. Favors sluggish or standing water. Active at night, feeding mainly on fish stunned by electric shocks. Described as a nocturnal piscivore that breeds during periods of high water; rarely feeds on molluscs (Ref. 44050). The electric organ, capable of discharging 300-400 V, is derived from pectoral muscle and surrounds almost the entire body. It is used both for prey capture and defense. Electric organ discharge (EOD) is intermittent and the amplitude increases with size of the fish (Ref. 10011). Responds immediately to cyclic light changes, exhibiting maximum EOD activity shortly after sunset and lowest activity just after sunrise (Ref. 10798). Its EOD duration decreased from 1.5 to 0.3 ms in response to increased temperature from 15 to 30°C (Ref. 10838). Adults form pairs and breed in excavated cavities or holes (Ref. 7248). Maximum size in Lake Chad reported as 1125mm SL, but most museum specimens much smaller (maximum 400mm SL, Nile River)(Ref. 57130).

fisheries: subsistence fisheries; gamefish: yes

Malapterurus electricus is a thickset fish with six mouth barbels and a single fin on its back, just anterior to the rounded tail fin. It is brownish or grayish, irregularly spotted with black, and attains a length and weight of about 1.2 metres (3 ft 11 in) and 23 kilograms (51 lb) M. electricus is capable of generating and controlling the discharge of up to 450 volts of electricity. It uses its power to defend itself and to capture prey.