Common helicopter catfish

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Common helicopter catfish
Wallago attu 1.jpg

Common helicopter catfish ( Wallago attu )

Systematics
Cohort : Otomorpha
Sub-cohort : Ostariophysi
Order : Catfish (Siluriformes)
Family : Real catfish (Siluridae)
Genre : Wallago
Type : Common helicopter catfish
Scientific name
Wallago attu
( Bloch & Schneider , 1801)

The Common helicopter Wels ( wallago attu ) is a species from the family of genuine catfish (Siluridae). It occurs in lakes and rivers from Pakistan to Vietnam and Indonesia from about 38 ° north to 10 ° south latitude. The species is fished commercially and by sport anglers and is considered to be threatened by overfishing .

features

Common helicopter catfish have an elongated body with a broad head and a strongly compressed snout. They are gray-brown on top with lighter sides and mostly white belly. They reach a length of up to 2.4 meters and a weight of up to 100 kilograms. The eyes are small. The mouth is large with angles that reach far behind the eye, and contains ligaments with numerous, conical teeth and two groups of teeth on the ploughshare . On the upper jaw there is a pair of long barbels that extend to the base of the anal fin . The barbels of the couple on the lower jaw reach about the angle of the mouth. The dorsal fin has four to six rays, the very long anal fin 77 to 97. The small pectoral fins have a hard ray and 12 to 15 soft rays. The gills have 24 to 30 gill spines and 18 to 21 Branchiostegalstrahl .

Way of life

The animals colonize large, calm to slowly flowing waters with sandy to muddy subsoil and can also penetrate into brackish water . They usually hide in hollows on the bank and hunt for food mainly on the bottom of the water. Young animals feed primarily on zooplankton and insects, while older animals eat crabs, molluscs and smaller fish. Threatened by humans, they defend themselves with powerful bites.

The spawning season is in the summer before the monsoons . In the Mekong, the animals migrate into smaller rivers and flooded areas during the flood period and return to deeper water when the water level drops.

Systematics

Bloch & Schneider described the species in 1801 as Silurus attu and depicted it on plate 75 of their Systema Ichthyologiae with a very precise copperplate engraving. The holotype or the dried skin preparation is cataloged in the Zoological Museum Berlin under catalog number 8793, but is currently lost.

swell

  • Martin Hochleithner: Catfish (Siluridae) - biology and aquaculture . Aqua tech Publications, Kitzbühel 2006, ISBN 3-9500968-7-6 , p. 76-77 .
  • Bloch, ME, & JG Schneider (1801): Systema Ichthyologiae iconibus cx illustratum. Post obitum auctoris opus inchoatum graduit, correxit, interpolavit Jo. Thank God Schneider, Saxo. Berolini. Sumtibus Auctoris Imprint et Bibliopolio Sanderiano Commissum. ME Blochii, Systema Ichthyologiae. : 387, pl. 75.
  • Common helicopter catfish on Fishbase.org (English)

Web links

Commons : Wallago attu  - album with pictures, videos and audio files