Alestes dentex (Linnaeus, 1758)
Status: Accepted name

Common names:
Characin
Local: Angara

Taxonomic tree
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii (ray-finned fish)
Order: Characiformes (Characins)
Family: Alestidae (African tetras)
Genus: Alestes
Species: Alestes dentex (Linnaeus, 1758)
Number of Occurrancies: 2

Etymology (based on Scharpf & Lazara, 2019)


  • Alestes: Greek for miller or grinder, presumably referring to inner row of premaxillary molariform teeth

  • dentex: with large teeth; name coined by Hasselquist (1757) in a work edited by Linnaeus, described as a toothed Cyprinus, referring to inner row of premaxillary molariform teeth

Synonyms: click here to view synonyms

Type locality: Nile River. Holotype at NRM

Distinguishing characters for the genus


  • Short snout

  • Small and non-protractile mouth; teeth firmly fixed, those of the outer series stout and not compressed basally

  • Two series of functional multi-cuspidate teeth in the upper jaw, the outer series usually tri-cuspid and less massive than the stout, many cusped teeth in the inner series 

Distinguishing characters for the species


  • Dorsal fin with 10-11 rays, the first two unbranched; its origin above pelvic-fin insertions (Diagnostic)

  • Gill rakers long, slender and fewer than Alestes baremose, 20-26 on the lower limb of the first gill arch (Diagnostic)

  • Depth of the body contained up to 3.5-4.75 times in standard length, and length of the head 4.5 (in young) to 6 times

  • Head 1.5 to twice as long as broad, and a well developed parietal fontanelle

  • Eye diameter 3.25 (in young) to 4 times in head length; well developed adipose lids

  • Maxilla not reaching the anterior orbital margin. 

  • 6 and 8 teeth in the outer and inner series of the upper jaw, 8 and 2 in these series in the lower jaw

  • Anal fin with 22-26 rays, the first three uncbranched.

  • Lateral line with 44-50 scales.

  • Color is silver, bluish-grey above. Dorsal fin grey, lower caudal lobe red, the posterior margin of both lobes outlined in black. In adult fishes, the pelvic and anal fins have an orange-red flush

Taxonomic remarks: The species closely resembles Alestes baremoze, but is differentiated by fewer gill rakers (compared to 27-38 in A. baremoze) and the dorsal fin origin that is above pelvic-fin insertions (compared to dorsal fin origin distinctly behind pelvic fin insertion in A. baremoze

Distribution in Uganda: Lake Albert, the Albert and Murchison Niles

Occurence: Native

Habitat: Pelagic; potamodromous

Feeding: Omnivorous, feeding on seeds, zooplankton, insects (chironomid larvae, coleopterans), fish fry, detritus and plants.  

Biology: Adult fishes range between 30-55 cm long. No information is available on breeding for the Ugandan populations. 

Economic importance/End use: The species is not common in catches

IUCN conservation status: click here to view IUCN status

Threats: Fishing

Main references


  • Greenwood PH. 1966. The fishes of Uganda. The Uganda Society, Kampala. 131 pages.

  • Sharpf C, Lazara J.K. 2019. Fish Name Etymology Database v17. www.etyfish.org

     



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Citation


Natugonza, V. & Musinguzi, L. (editors) 2021. Freshwater Biodiversity Portal for Uganda. www.freshwaterbiodiversity.go.ug, version (01/2021).

Contact


National Fisheries Resources Research Institute (NaFIRRI)
P.O Box 343, Jinja, Uganda
Telephone: +256 434 121369 / +256 434 120484
General Inquiries: inquiries@freshwaterbiodiversity.go.ug
Technical Support: info@freshwaterbiodiversity.go.ug,
Physical Location: Nile Crescent, Opposite the wagon ferry Terminal, Plot 39/45, Jinja, Uganda