Quiver catfish

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Quiver catfish
Shiver catfish (Malapterurus electricus)

Shiver catfish ( Malapterurus electricus )

Systematics
Cohort : Otomorpha
Sub-cohort : Ostariophysi
Order : Catfish (Siluriformes)
Family : Electric catfish (Malapteruridae)
Genre : Malapterurus
Type : Quiver catfish
Scientific name
Malapterurus electricus
( Gmelin , 1789)

The quiver catfish or electric catfish ( Malapterurus electricus ) is a predatory fish from the family of electric catfish (Malapteruridae), which currently has 21 species. The Latin name of the species, electricus, alludes to the fish's ability to deliver sensitive electric shocks to its prey and predators .

features

The trembling catfish can reach a maximum body length of 122 cm with a weight of 20 kg. Its scaly body is elongated to cylindrical and gray-brownish in color on the back. The sides of the body are flesh-colored and covered with numerous black dots, which become increasingly larger towards the tail. The ventral side, pectoral and pelvic fins are yellowish-white or reddish, the caudal fin at the base dark, then orange-yellow with a red border. The head is slightly flattened, the eyes are small. Six barbels sit under the head , one dorsal fin is missing. The pectoral, ventral and caudal fins are rounded. The pectoral fins are carried by 8 or 9 fin rays, the ventral fins by 6 fin rays. The latter sit about halfway between the tip of the snout and the base of the caudal fin. The caudal fin has 9 to 10 rays. Fin spines are absent in all fins. The adipose fin is low and has a rounded trailing edge. The muscles that generate electricity ( electroplax ) are located directly under the skin and cover the entire body, except for the fins and head. They are covered by a layer of current-repellent skin, which is supposed to prevent the fish from being harmed by its own electrical surges. The electric shocks can be generated and delivered at any muscle point at any time. They reach a voltage of 350 to 450  volts .

Distribution and habitat

The trembling catfish is native to West and Central Africa. Its distribution area extends from the Senegal river basin via the Bandama , Niger , Lake Chad and the Nile basin (but not in Lake Victoria ) to Lake Turkana . It occurs mainly in water zones near the bank, where it prefers fast to slow flowing, cloudy habitats . He likes to stay there between rocks and roots reaching into the water.

Lifestyle and diet

Little is known about the mode of reproduction. The quiver catfish digs shallow pits up to 3 m long in clay bank banks that are 1–3 m deep in the water and in which the spawn is laid.

The quiver catfish is nocturnal . The main activity time is a few hours after sunset. The quiver catfish primarily hunts smaller fish, which it surprises by sneaking up and then being electrocuted and swallowed whole. He eats all kinds of fish.

The males of this species show a very pronounced territorial behavior. Any conspecific who is equal in height and weight to the owner of the territory is kept energetically at a distance; If the rejection attempts are unsuccessful, it is not uncommon for comment fights in which bodies, barbels and electric shocks are used. Prey fish that are too big to be eaten and that hunt small fish themselves (foreign food competitors) are also driven away by threatening gestures and short electric shocks.

Systematics and risk

In the classical system, the quiver catfish is placed in the superfamily Siluroidea . According to molecular biological investigations, he belongs within the subordination of the Siluroidei to the “Big Africa” group. The quiver catfish is generally classified as “not endangered”, but in Egypt , especially in the Nile Delta , the population is endangered by excessive salt in the delta brackish water and by the release of poisonous chemicals from industrial plants .

Economical meaning

Even today, the species is regionally popular as a food fish . For inexperienced and inattentive fishermen, attempting to catch the trembling catfish can have harmful consequences due to its electrical capabilities. Furthermore, the electrical muscles are at the center of studies on neuronal metabolism, axonal transport and the release of transmitters within the electrical muscle cells.

useful information

The species was already known to the ancient Egyptians . Representations of the quiver catfish have been handed down from the early days, numerous, very detailed relief images come from the Old Kingdom . These suggest that the Egyptians were apparently familiar with the electric power of the trembling catfish: fishermen only caught the animals with palm fiber strings or in nets and beat them to death before they even took the fish out of the water. The early Egyptian King Narmer ( 1st Dynasty ) used a quiver catfish representation as a name sign.

literature

  • Maurice Burton, Robert Burton: International Wildlife Encyclopedia. Marshall Cavendish, 2002, ISBN 978-0761472667 .
  • Hans-Jochim Franke: Handbook of Welskunde. Urania-Verlag, 1985.
  • Richard Owen : On the Anatomy of Vertebrates. Vol. I. Fishes and Reptiles. (= Reprint of Volume 1 by Richard Owen: On the Anatomy of Vertebrates . Longmans, Green, and Co., London 1866) Cambridge University Press, 2011 ISBN 1108038255 .
  • Dietrich Sahrhage: Fishing and fish cult in ancient Egypt (= cultural history of the ancient world , vol. 70). von Zabern, Mainz 1998, ISBN 3-8053-1757-3 .

Web links

Commons : Malapterurus electricus  - collection of images, videos and audio files

Individual evidence

  1. ↑ Malapteruridae on Fishbase.org (English)
  2. ^ Maurice Burton, Robert Burton: International Wildlife Encyclopedia. Marshall Cavendish, 2002, ISBN 978-0761472667 .
  3. ↑ a b c d e f g Malapterurus electricus in the Animaldiversity database
  4. ↑ Hans-Jochim Franke: Handbook of Welskunde. Urania-Verlag, 1985.
  5. ^ A b c Richard Owen: On the Anatomy of Vertebrates . P. 355.
  6. ↑ Zitterwels on Fishbase.org (English)
  7. ↑ Malapterurus electricus in the IUCN Red List of Endangered Species 2012.2. Posted by: A. Azeroual, M. Entsua-Mensah, A. Getahun, P. Lalèyè, J. Kazembe, 2010. Retrieved June 6, 2013.
  8. ↑ Dietrich Sahrhage: Fishing and fish cult in ancient Egypt . P. 69.