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Electric catfish or Malapteruridae is a
The Malapteruridae are the only group of catfish with well-developed
The electric catfish of the Nile was well known to the ancient Egyptians. The Egyptians reputedly used the electric shock from them when treating
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
of catfish
Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the three largest species alive, ...
es (order Siluriformes). This family includes two genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...
, '' Malapterurus'' and '' Paradoxoglanis'', with 21 species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...
. Several species of this family have the ability to generate electricity, delivering a shock of up to 350 volt
The volt (symbol: V) is the unit of electric potential, electric potential difference (voltage), and electromotive force in the International System of Units (SI). It is named after the Italian physicist Alessandro Volta (1745–1827).
Defin ...
s from its electric organ
An electric organ, also known as electronic organ, is an electronic keyboard instrument which was derived from the harmonium, pipe organ and theatre organ. Originally designed to imitate their sound, or orchestral sounds, it has since develope ...
. Electric catfish are found in tropical Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
and the Nile River
The Nile, , Bohairic , lg, Kiira , Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered the longest riv ...
. Electric catfish are usually nocturnal
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite.
Nocturnal creatures generally have highly developed sens ...
and carnivorous. Some species feed primarily on other fish, incapacitating their prey with electric discharges, but others are generalist bottom foragers, feeding on things like invertebrates, fish eggs, and detritus
In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts comm ...
. The largest can grow to about 1.2 meters (3 ft) long, but most species are far smaller.
Description
The Malapteruridae are the only group of catfish with well-developed electrogenic
Electroreception and electrogenesis are the closely-related biological abilities to perceive electrical stimuli and to generate electric fields. Both are used to locate prey; stronger electric discharges are used in a few groups of fishes to stu ...
organs; however, electroreceptive systems are widespread in catfishes. The electrogenic organ is derived from anterior body musculature and lines the body cavity. Electric catfish do not have dorsal fins or fin spines. They have three pairs of barbels (the nasal pair is absent). The swim bladder
The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled organ that contributes to the ability of many bony fish (but not cartilaginous fish) to control their buoyancy, and thus to stay at their current water depth wit ...
has elongate posterior chambers, two chambers in '' Malapterurus'' and three in '' Paradoxoglanis''.
''Malapterurus'' have been conditioned by means of reward to discharge on signal. As reported in the ''New York Times'', April 2, 1967, a researcher, Dr. Frank J. Mandriota of City College, New York, conditioned an ''M. electricus'' to discharge on a light signal for a reward of live worms delivered automatically. This is the first conditioning that modified neither glandular nor muscular responses.
The largest can grow to about 1.2 meters (3 ft) and . Most ''Malapterurus'' and all ''Paradoxoglanis'' species are much smaller, reaching less than long.
Relationship to humans
The electric catfish of the Nile was well known to the ancient Egyptians. The Egyptians reputedly used the electric shock from them when treating arthritis
Arthritis is a term often used to mean any disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, swelling, and decreased range of motion of the affected joints. In som ...
pain. They would use only smaller fish, as a large fish may generate an electric shock from 300 to 400 volts. The Egyptians depicted the fish in their mural painting
A mural is any piece of graphic artwork that is painted or applied directly to a wall, ceiling or other permanent substrate. Mural techniques include fresco, mosaic, graffiti and marouflage.
Word mural in art
The word ''mural'' is a Spanis ...
s and elsewhere; the first known depiction of an electric catfish is on a slate palette of the predynastic Egyptian ruler Narmer
Narmer ( egy, Wiktionary:nꜥr-mr, nꜥr-mr, meaning "painful catfish," "stinging catfish," "harsh catfish," or "fierce catfish;" ) was an ancient Egyptian pharaoh of the Early Dynastic Period (Egypt), Early Dynastic Period. He was the successor ...
about 3100 BC.
An account of its electric properties was given by an Arab physician of the 12th century; then as now, the fish was known by the suggestive name of , which means "thunder" (literally 'trembler' or 'shaker').
The shock of these catfish is used to stun prey and in defense. It is not known to be fatal to humans, but large electric catfish can stun an adult person. In small electric catfish, the generated current is far less and only feels like a tingle to humans.
References
{{Taxonbar, from=Q1326591 * Strongly electric fish Taxa named by Pieter Bleeker