Common names:
Longnose stonebasher
Lunyoro/Lunyara/Lango/Ludope: Nkoiro Lukenyi: Mpumbi Luganda: Ekumbi

Taxonomic tree
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii (ray-finned fish)
Order: Osteoglossiformes (Fishes with bony tongue)
Family: Mormyridae (fishes with Elephant-like snout)
Genus: Gnathonemus
Species: Gnathonemus longibarbis (Hilgendorf, 1888)
Number of Occurrancies: 69

Etymology(based on Sharpf & Lazara, 2018)

• Gnathonemus: gnathos, jaw; nema, thread, referring to lower jaw with a “conical flap or barbel”


• longibarbis: longus, long; barbis, barbel, referring to longer barbels (nearly equal to snout length) than Mormyrus (=Marcusenius) ussheri

Synonyms:click here to view synonyms

Type locality: Lake Victoria, Ukerewe (Kageyi, east of Kayenze, southern shore of Lake Victoria), Tanzania. Holotype at Zoologisches Museum Berlin (ZMB) 

General identification features for mormyrids: Elongate body; narrow and distinct caudal peduncle; opercular bones hidden beneath the skin, reduced opening of the branchial cabity reduced; small eyes covered by the skin; naked head, its skin thick and well supplied with mucus glands; small cycloid scales; and muscles of the caudal peduncle modified to form an electric organ, and the elaphant-like snout.

Distinguishing characters for the genus

• Lower jaw extending beyond the upper jaw


• Chin with a long fleshy appendage

Distinguishing characters for the species

• Depth of the body contained up to 3.66-5 times in standard length, and length of the head (excluding the lower lip) 4-4.5 times


• Upper head profile gently curved


• Snout 1/2-3/4 length of post-ocular part of the head


• Chin produced into a long, cyrindrical and fleshy appendage which is as long as, or longer than the snout (Diagnostic)


• Mouth terminal; teeth in a single series restricted to the middle of each jaw, small and notched, 3-5 and 4-6 in the upper and lower jaws, respectively


• Dorsal fin with 22-25 rays, its origin is slightly behind the insertion the anal fin


• Anal fin with 28-31 rays


• Caudal fin with pointed lobes, and almost entirely covered with small scales


• Lateral line with 58-64 scales; 10-12 around the caudal peduncal, which is 2-2.5 times longer than deep


• Colour is variable depending on habitat, but typically dark brown, lighter ventrally

Distribution in Uganda: Lake Victoria basin, Victoria Nile and Lake Kyoga

Occurence: Native

Habitat: Demersal, inhabiting waters just above the bottom; common in shallow inshore waters over both sandy and rocky bottoms; potamodromous. In Lake Kyoga, the species is abundant in water-lily swamps.

Feeding: Primarily insectivorous, feeding mainly on insect larvae especially of chironomidae and odonata, but can also feed     on marginal vegetation, arthropods, oligochaetes and fish eggs

Biology: Sexually mature fishes range between 23-36 cm long. The species migrates up the river during the rainy seasons to spawn; spawning typically occurs twice a year in upstream waters during rainy seasons.   

Economic importance/End use: Local subsistence (for food).

IUCN conservation status: Click here to view IUCN status

Threats: River damming for hydro-electric power generation; Clearence of papyrus swamps and marginal wetlants; fishing of juveniles for baits in the Nile perch fishing industry.

Main references

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


• Sharpf C, Lazara J.K. 2018. Fish Name Etymology Database v16. www.etyfish.org.