African flag knifefish

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African flag knifefish
Papyrocronus afer.jpg

African flag knifefish ( Papyrocranus afer )

Systematics
Overcohort : Osteoglossomorpha (Osteoglossomorpha)
Order : Bony tongues (Osteoglossiformes)
Subordination : Knifefish-like (Notopteroidei)
Family : Old World Knifefish (Notopteridae)
Genre : Papyrocranus
Type : African flag knifefish
Scientific name
Papyrocranus afer
( Günther , 1868)

The African flag knifefish ( Papyrocranus afer ) is an African freshwater fish from the Old World knifefish family (Notopteridae). It occurs in two separate areas of distribution in West Africa. One extends from Senegal and Gambia to the Tano in Ghana, the second includes Niger , Benue , Cross-River and Sanaga and extends from Nigeria to Cameroon . It is absent in the intervening Volta system. In the Congo Basin, the species is replaced by Papyrocranus congoensis .

features

The African flag knife fish grows to a maximum of 80 cm and can be easily distinguished from the African knife fish ( Xenomystus nigri ), the second knife fish species in its range, by the short, flag-like dorsal fin, which is supported by 6 to 7 fin rays . The body is strongly flattened at the sides, the back line is curved. The head length is about a fifth of the standard length . As with all knife fish, the long anal fin, which has grown together with the caudal fin, is the main driving organ. The fin has 113 to 141 fin rays. Ventral fins are missing. The top of the head is slightly concave, the length of the snout corresponds to the diameter of the eye. The big mouth extends below the center of the eye. The nostrils terminate in tubular tentacles, the nasal tentacles can be twice as long as the diameter of the eyes. The number of Branchiostegal rays is 7 to 9, the number of gill pelvis rays on the lower branch of the first gill arch is 12 to 14 and the number of vertebrae is 79 to 85 (of which 63 to 69 tail vertebrae).

Young fish are olive gray to reddish in color and show dark spots or a dark network. Older animals are usually monochrome purple-brown to black and in some cases show numerous bright spots on the sides and on the anal fin.

  • Scale formula : mLR 130–165, 38 to 47 ventral scales form a sawn ventral edge.

literature

  • Melanie Stiassny, Guy Teugels & Carl D. Hopkins: The Fresh and Brackish Water Fishes of Lower Guinea, West-Central Africa, Volume 1. ISBN 9789074752206
  • Günther Sterba : The world's freshwater fish. 2nd Edition. Urania, Leipzig / Jena / Berlin 1990, ISBN 3-332-00109-4 .

Web links