Class: Actinopterygii (ray-finned fish)
Order: Characiformes (Characins)
Family: Alestidae (African tetras)
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
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
- 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