Brycinus

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Brycinus
Brycinus macrolepidotus, the type species of the genus.

Brycinus macrolepidotus , the type species of the genus.

Systematics
Cohort : Otomorpha
Sub-cohort : Ostariophysi
Otophysa
Order : Tetras (Characiformes)
Family : African tetras (Alestidae)
Genre : Brycinus
Scientific name
Brycinus
Valenciennes in Cuvier & Valenciennes, 1850

Brycinus is a genus of fish from the family of the African tetras (Alestidae). The species live in fresh waters of tropical Africa .

features

Brycinus species have an elongated, silvery body and are 6.3 to 30 cm long. In contrast to the genus Alestes , their nictitating membrane is reduced and difficult to see, and the swim bladder does not reach behind the anus and into the tail fin stalk. The scales have radius-shaped depressions that are always connected to each other (not with Alestes ). The dorsal fin begins above or just behind the base of the pelvic fin , more or less above the center of the body. In the males, the fin rays are often elongated. There are two rows of teeth in both jaws.

Depending on the shape of the fontanel of the front parietal bone , three groups can be distinguished within the genus. In the B. nurse group, whose species become medium-sized in most cases, the fontanel is closed in adult fish and in the large species of the B. macrolepidotus group it is closed in young animals. In the B. nurse group, as in Alestes , the sexes can also be differentiated by the shape of the anal fin (convex in males, straight or concave in females); in the B. macrolepidotus group it is the same in both sexes.

Way of life

Brycinus species live as schooling fish in lakes and rivers in the middle and upper water layers.

species

A total of around 30 species belong to the genus Brycinus . The genus is not a monophylum , but is divided into two groups of species, which differ in size, morphology and phylogenetic position.

Brycinus macrolepidotus species group; Large, with a closed fontanel in the frontoparietal (a skull bone) and without a sexual dimorphism touching the anal fin .

Brycinus nurse species group; medium-sized, with an open fontanel in the frontoparietal of the juvenile fish and a different anal fin shape in males and females.

The former Brycinus longipinnis species group around the long- fin tetra, known from aquaristics , now forms the independent genus Bryconalestes .

literature

  • Günther Sterba : Freshwater fish in the world . Urania Verlag., Leipzig 1990; Licensed edition for Weltbild Verlag GmbH, Augsburg 1995, ISBN 3-89350-991-7 .
  • Melanie Stiassny, Guy Teugels & Carl D. Hopkins: The Fresh and Brackish Water Fishes of Lower Guinea, West-Central Africa, Volume 1. ISBN 978-90-74752-20-6

swell

  1. ↑ Koné, T. & Vreven, E. 2013. A morphological revision of the Brycinus macrolepidotus (Valenciennes, 1850) group (Characiformes: Alestidae) reveals unexpected species diversity. Fifth International Conference of the Pan African Fish and Fisheries Association (PAFFA5).
  2. ↑ a b Melanie Stiassny, Guy Teugels & Carl D. Hopkins: The Fresh and Brackish Water Fishes of Lower Guinea, West-Central Africa, Volume 1. ISBN 9789074752206 , page 351 u. 364.
  3. ^ Zanata, AM and RP Vari (2005): The family Alestidae (Ostariophysi, Characiformes): a phylogenetic analysis of a trans-Atlantic clade. Zoological Journal of the Linnean Society v. 145: 1-144.

Web links

Commons : Brycinus  - collection of images, videos and audio files