Gymnarchus niloticus Cuvier, 1829

Open encyclopedia reference

Gymnarchus niloticus – the aba, aba aba or frankfish – is an electric fish, living at the bottoms of rivers and lakes. It is the only species in the genus Gymnarchus and the family Gymnarchidae, within the order Osteoglossiformes. It is a long slender fish with no pelvic or anal fins, and a tail fin shaped like a rat's tail. It swims using its elongated dorsal fin, allowing it to keep its body straight while it moves. This in turn enables it to produce a steady but weak electric field, which it uses to locate its prey. It is large for a river fish; adults can reach 1.6 m (5.2 ft) in length and 19 kg (42 lb) in weight. In 1950, Hans Lissmann noticed that the fish could swim equally well forwards or backwards, clearly relying on a sense other than vision. He demonstrated that it could locate prey by electroreception, making it the first fish known to have this ability.

Wikipedia contributors, Gymnarchus; see linked history · CC BY-SA 4.0 . Plain-text lead excerpt, at most 180 words; no infobox or later sections Retrieved 2026-10-05T22:40:36.946150+00:00. This reference remains separate from the taxonomic record.

Identity & source status

Scientific name

Gymnarchus niloticus Cuvier, 1829

Name authority

Cuvier, 1829

Rank

species

Accepted status

accepted

Kingdom

Animalia

Phylum

Chordata

Class

Teleostei

Order

Osteoglossiformes

Family

Gymnarchidae

Genus

Gymnarchus

Extinction status

Not supplied by this source

Source habitat flags: Marine: no · Freshwater: yes · Terrestrial: no. These do not form a complete habitat description.

Classification family tree

Nested taxonomic groups from the source. This is not a direct-ancestor chain, a dated evolutionary tree or a phylogenetic reconstruction.

1. domainEukaryota (Chatton, 1925) Whittaker & Margulis, 1978
2. kingdomAnimalia
3. phylumChordata
4. subphylumVertebrata
5. infraphylumGnathostomata
6. parvphylumOsteichthyes
7. gigaclassActinopterygii
8. superclassActinopteri
9. classTeleostei
10. orderOsteoglossiformes
11. familyGymnarchidae Bleeker, 1859
12. genusGymnarchus Cuvier, 1829
13. speciesGymnarchus niloticus Cuvier, 1829

Close classified relatives

No other member of this genus is present in the selected snapshot.

Browse 1 records assigned to Gymnarchidae.

Names & synonyms

Names explicitly linked to this accepted taxon in the source. Synonymy can change with revision.

Source literature & publication evidence

References attached to this source record, including nomenclatural citations where supplied. This is a selected bibliography; abbreviated citations remain in the source’s form.

1. Cuvier, G. (1829). Le Règne Animal distribué, d’apres son organisation, pour servir de base à l’histoire naturelle des animaux et d’introduction à l’anatomie comparée. [The Animal Kingdom, arranged according to its organization, to serve as a basis for the natural history of animals and as an introduction to comparative anatomy]. Déterville, Paris, Edition 2. v. 2: i–xv + 1–406. https://doi.org/10.5962/bhl.title.1964 Source fields: Taxon.tsv dwc:namePublishedIn, Taxon.tsv dcterms:references

Origins, evidence & remaining research

Name authority and publication references document nomenclature where the source supplies it. They do not establish evolutionary origins or the earliest fossil occurrence.

Specimen-level evidence, morphology, ecological research, phylogenetic studies, a comprehensive bibliography and a located literary passage have not yet been compiled for this record. A suitable sourced image remains to be added.

Dataset citation & attribution

This exact taxon in ChecklistBank · Catalogue of Life 2026-09-11

Catalogue of Life 2026-09-11; dataset 316321; doi:10.48580/dgz5n. https://creativecommons.org/licenses/by/4.0/ . Retrieved 5 October 2026.

Stable key: col:3HPF4. Classification follows source parent identifiers. English common names may vary by region.