Oreochromis niloticus

Super Group: 
Opisthokonta
Phylum: 
Chordata
Sub-Phylum: 
Vertebrata
Class: 
Actinopteri
Sub-Class: 
Neopterygi
Order: 
Perciformes
Sub-Order: 
Labroidei
Family: 
Anostomidae
Sub-Family: 
Cichlidae
Genus: 
Oreochromis
Species: 
niloticus
Authority: 
Linnaeus 1758
Synonym(s): 
Perca nilotica (Linnaeus, 1758)

Diagnosis

Diagnosis_Genus: Oreochromis Günther. B. 5, D. I7/II. A. 4/I0. P. I5. L. lat. 35. L. transv. 5/I5. The height of the body is nearly equal to the length of the head, and on third of the total length, without caudal. Snout much longer than the eye, the praeorbital being longer than, and as high as, the orbit. The teeth in the upper jaw form a broad villiform band, those of the outer series being a little stronger then the others. These stronger teeth, which are thirty-eight in number on each side, have the crown slightly compressed, some showing a distinct notch and being brown at the tip. Interorbital space twice as broad as the orbit, convex. Scales on the cheek rather small, in three series; sclaes cycloid, of moderate size; the lateral line is interrupted below the end of the spinous dorsal. Dorsal spines gradually increasing in length; the sixth ray is the longest, eaching backwards to the root of the caudal; pectoral and ventral fins long, extending to, or nearly to, the anal. Coloration uniform dusky, but some of the scales on the back seem to have had a reddish-brown spot at the base.
Diagnosis_Species: Perca nilotica Linnaeus. P. pinnis dorsalibus subdistinctis, caudae integra. Mus. Ad. Fr. 2.p. D.8, 1/9. P. 14. V. 6. A. 3/13. C15. Hasselqv. iter. 359 . n. 83. Perca nilotica. D.8, 1/13. P. 16. V. 1/6, A. 3/12. C. 20. Habitat in Nilo. Hasselqvist. *dorso moxopterygio, cauda indivisa.

Body_adults_length : 20 cm (Bwanika et al. 2004)
Body_adults_max_length: 62 cm
Body_eggs_length: 2.12 mm - 2.69 mm (mature eggs)
Weight_Max: 3.65 kg
Sequence_Rex1: AJ288471, AJ288472 AJ288473, AJ288474, AJ288475, AJ288476, AF155735 (Schneider et al 2013)
Sequence_Rex3: AJ400368, AJ400369, AJ400370, AJ400371, AJ400372 (Schneider et al 2013)
Sequence_Rex6: AJ293545, AJ293546, AJ293547 (Schneider et al 2013)

Etymology

Oreochromis: Latin, aurum = gold + Greek, chromis = a fish, perhaps a perch;  niloticus: From "Filhoa" = the Amharic word for "hot spring"

Type species

The type species of the genus Oreochromis is Oreochromis hunteri (Günther, 1889).

Type illustration / Type locality / Type specimen

Type locality: Nile River.

Ecology

Habitat: Freshwater, Estuarine
Habitat: Africa: naturally occurring in coastal rivers of Israel, Nile basin (including lake Albert, Edward and Tana), Jebel Marra, Lake Kivu, Lake Tanganyika, Awash River, various Ethiopian lakes, Omo River system, Lake Turkana, Suguta River and Lake Baringo. In West Africa natural distribution covers the basins of the Senegal, Gambia, Volta, Niger, Benue and Chad, with introduced specimens reported from various coastal basins. Widely introduced for aquaculture, with many existing strains. Several countries report adverse ecological impact after introduction. Occur in a wide variety of freshwater habitats like rivers, lakes, sewage canals and irrigation channels.
Substrate: water
Salinity: freshwater
Migratory: Highly migratory species
Causality_of_migration: Sexual reproduction
Temporality_of_migration: Pluri-annual
Temperature: 13-35 °C (optimal 31-36 °C, 24°C for sexual reproduction)
pH: 5-9
Depth: Epipelagic
Oxygen_level: Oxic

Life cycle

Reproduction_mode: sexual
Longevity: more than 3 years (longer than 10 years)
Generation_time: 3 to 12 months (3-6 months depending on temperature, reaching about 30 g)
Fertility_period: Pluri-annual (every 30 days) (Reproduction occurs only when temperatures are over 20°C)
Spawning_method: External fertilization in the water column (Females incubate eggs inside their mouths (approximately for a week) where larvae hatch and remain until the vitellus is reabsorved. Spawns in firm sand in water from 0.6 to 2 m deep of lakes and inshore waters. A single male probably fertilises the eggs of more than one female. Eggs are shed in batches in shallow nest and fertilized by male)
Fecundity_number_of_eggs: 73 to 1 810 eggs per female with a mean fecundity of 815 eggs. Female carries up to 200 eggs in her mouth.

Feeding behaviour

Filter feeder
Herbivorous

Mode of locomotion

Motility: motile_swimming

Reference(s)

On some fishes from the Kilima-njaro district.

Günther (1889) On some fishes from the Kilima-njaro district. In: Proceedings of the Scientific Meetings of the Zoological Society of London. MESSRS, Longmans, Green, and Co., London,

Observation site(s)