Teleostei (teleosts) > Characiformes
(Characins) > Alestidae
Etymology: Hydrocynus: Greek, hydr = water + Greek, kyon = dog (Ref. 45335).
More on author: Castelnau.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; demersal; potamodromous (Ref. 51243). Tropical; 22°C - 28°C (Ref. 12468)
West-Africa: Niger, Bénoué, Ouémé, Senegal (Ref. 2880, 5331, 7248, 81279), Ouémé (unconfirmed, Ref. 81279), Chad (Ref. 2880, 5331, 81279). Also found in the Volta (Ref. 5331, 81279) and Mono rivers (Ref. 81279). Lower Guinea: Cross and Sanaga basins (Ref. 80290). Widespread throughout the Congo River basin (Ref. 4910, 41585, 41594, 42510, 45616, 52070, 89725, 106290). Also reported from Nile, Omo, Zambezi, Limpopo, Rovuma, Shire, Rufiji, Ruaha, Lake Tanganyika, Lake Rukwa (Ref. 2880, 80290), Lake Albert (Ref. 4903) and Lake Kariba (Ref. 27602), Malagarazi, Okavango and lower reaches of coastal systems south to the Pongolo (Ref. 7248).
Length at first maturity / Size / Weight / Age
Maturity: Lm 39.8  range ? - ? cm
Max length : 105 cm FL male/unsexed; (Ref. 40637); 74.0 cm FL (female); max. published weight: 28.0 kg (Ref. 40637); max. reported age: 8 years (Ref. 2754)
soft rays: 15. Diagnosis: large fang-like teeth overlapping the jaws when the mouth is closed; gill-rakers long, about equal to the length of gill filaments; body generally > 22% of SL (Ref. 28714). 43-53 scales in lateral line; 2 scale rows between lateral line and scaly process at pelvic-fin bases; eye < 70% of interorbital space (Ref. 2880, 81279). Dorsal-fin origin at about same level as pelvic-fin insertions (Ref. 2880, 80290, 81279). Gill rakers few (5-9/9-12) but rather long (Ref. 2880, 80290, 81279), about equal to the length of gill filaments (Ref. 28714). Tips of adipose and dorsal fins black; forked edge of caudal fin black (Ref. 2880, 80290, 81279). Dark caudal fin coloration may also extend unto median caudal rays, forming crescent-shaped blotch (Ref. 80290, 81279). Dark longitudinal streaks present above the lateral line (Ref. 28714).
Prefers warm, well-oxygenated water, mainly larger rivers and lakes; all but the largest form roving schools of like-sized fish; aptly described as fierce and voracious; diet increasingly piscivorous, becoming exclusive fish feeders when above 90-100 mm length; feeds on whatever prey is most abundant but Brycinus, Micralestes, Barbus, and Limnothrissa are favored (Ref. 7248, 52193). Piscivorous, but may also eat Caridina and insects (Ref. 28714). Useful food fish in some areas (Ref. 4967).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Paugy, D. and S.A. Schaefer, 2007. Alestidae. p. 347-411. In M.L.J. Stiassny, G.G. Teugels and C.D. Hopkins (eds.) Poissons d'eaux douces et saumâtres de basse Guinée, ouest de l'Afrique centrale/The fresh and brackish water fishes of Lower Guinea, west-central Africa. Vol. 1. Coll. Faune et Flore tropicales 42. Istitut de recherche pour le développement, Paris, France, Muséum nationale d'histoire naturelle, Paris, France and Musée royale de l'Afrique centrale, Tervuren, Belgique. 800 p. (Ref. 80290)
IUCN Red List Status (Ref. 126983)
Threat to humans
Fisheries: commercial; gamefish: yes
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82804
= 0.5312 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01096 (0.00869 - 0.01383), b=3.01 (2.95 - 3.07), in cm total length, based on LWR estimates for this species (Ref. 93245
Trophic level (Ref. 69278
): 4.4 ±0.0 se; based on diet studies.
Generation time: 3.7 (3.0 - 5.0) years. Estimated as median ln(3)/K based on 14 growth studies.
Resilience (Ref. 120179
): Medium, minimum population doubling time 1.4 - 4.4 years (K=0.20-0.30; tmax=11).
Fishing Vulnerability (Ref. 59153
): Moderate vulnerability (41 of 100).
Nutrients (Ref. 124155
): Calcium = 69.1 [24.4, 163.4] mg/100g ; Iron = 1.47 [0.76, 3.56] mg/100g ; Protein = 19.5 [17.4, 21.7] % ; Omega3 = 0.462 [0.179, 1.253] g/100g ; Selenium = 75 [30, 165] μg/100g ; VitaminA = 30.6 [9.0, 102.8] μg/100g ; Zinc = 0.887 [0.602, 1.339] mg/100g (wet weight);