Advertisement

You can sponsor this page

Gymnarchus niloticus  Cuvier, 1829

Aba
Upload your photos and videos
Pictures | Stamps, Coins | Google image
Image of Gymnarchus niloticus (Aba)
Gymnarchus niloticus
Picture by Moreau, J.

Classification / Names Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa

Actinopterygii (ray-finned fishes) > Osteoglossiformes (Bony tongues) > Gymnarchidae (Abas)
Etymology: Gymnarchus: Greek, gymnos = naked + Greek, archos = anus (Ref. 45335).   More on author: Cuvier.

Environment / Climate / Range Ecology

Freshwater; demersal; pH range: 6.5 - 8.0; dH range: 10 - 25; potamodromous (Ref. 51243).   Tropical; 23°C - 28°C (Ref. 13614); 18°N - 5°N

Size / Weight / Age

Maturity: Lm ?  range ? - ? cm
Max length : 167 cm SL male/unsexed; (Ref. 2915); max. published weight: 18.5 kg (Ref. 2915)

Short description Morphology | Morphometrics

Dorsal spines (total): 0; Dorsal soft rays (total): 183-230. Body depth 7.2-10.3 x SL. Head 5.6-6.9 x SL. Snout prominent. Pectorals 1.9-5.0 x head length. Body terminates in thin point. Head without scales. Scales small.

Distribution Countries | FAO areas | Ecosystems | Occurrences | Point map | Introductions | Faunafri

Africa: occurring widely in the Nile, Niger, Volta, Chad, Senegal and Gambia basins and Lake Rudolf.

Biology     Glossary (e.g. epibenthic)

Following flooding of the river banks (Gambia River), this species builds large elliptical floating nests in densely vegetated swamps at depths of about 1-1.5 m; lays about 1000 `amber-like' eggs; larvae hatching after 5 days (Ref. 10609). Feeds on crustaceans, insects and fish (Ref. 28714). No pelvic, anal or caudal fins. Possesses an electric organ that extends along almost the entire trunk to the tip of the tail (Ref. 10840). Also equipped with ampullary receptors and two types of tuberous receptors for electroreception (Ref. 10841). Showed increased electric organ discharge (EOD) rate by 50-60 Hz between 21 and 31°C (Ref. 10837).

Main reference Upload your references | References | Coordinator | Collaborators

Bigorne, R., 1990. Gymnarchidae. p. 185-186. In C. Lévêque, D. Paugy and G.G. Teugels (eds.) Faune des poissons d'eaux et saumâtres d'Afrique de l'Ouest. tome 1. Faune Trop. 28. Musée Royal de l'Afrique Centrale, Tervuren, Belgique and ORSTOM, Paris.

IUCN Red List Status (Ref. 90363)

CITES (Ref. 94142)

Not Evaluated

Threat to humans

  Harmless




Human uses

Fisheries: commercial
FAO(Aquaculture: production; fisheries: production; publication : search) | FisheriesWiki | Sea Around Us

More information

Countries
FAO areas
Ecosystems
Occurrences
Introductions
Stocks
Ecology
Diet
Food items
Food consumption
Ration
Common names
Synonyms
Metabolism
Predators
Ecotoxicology
Reproduction
Maturity
Spawning
Fecundity
Eggs
Egg development
Age/Size
Growth
Length-weight
Length-length
Length-frequencies
Morphometrics
Morphology
Larvae
Larval dynamics
Recruitment
Abundance
References
Aquaculture
Aquaculture profile
Strains
Genetics
Allele frequencies
Heritability
Diseases
Processing
Mass conversion
Collaborators
Pictures
Stamps, Coins
Sounds
Ciguatera
Speed
Swim. type
Gill area
Otoliths
Brains
Vision

Tools

Special reports

Download XML

Internet sources

Estimates of some properties based on empirical models

Phylogenetic diversity index (Ref. 82805):  PD50 = 1.5000   [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00380 (0.00148 - 0.00976), b=3.09 (2.87 - 3.31), based on LWR estimates for this Subfamily-BS (Ref. 93245).
Trophic Level (Ref. 69278):  3.7   ±0.58 se; Based on food items.
Resilience (Ref. 69278):  Low, minimum population doubling time 4.5 - 14 years (K=0.12-0.17).
Vulnerability (Ref. 59153):  High to very high vulnerability (71 of 100) .
Price category (Ref. 80766):   Unknown.