ragfish

Open encyclopedia reference

The ragfish (Icosteus aenigmaticus) is a ray-finned fish of the northern Pacific Ocean; although classified as a bony fish, its skeleton is mostly cartilage, and the larvae have pelvic fins that disappear as they mature. It is the sole member of the family Icosteidae within the order Scombriformes. The ragfish body is scaleless and limp, because of its cartilaginous skeleton and its flabby muscles. None of the fins have any spines. The dorsal and anal fins extend much of the length of the body, while the pelvic fins are absent. The coloration is generally a dark brown, and maximum known length is 2 m. Ragfishes are found on the bottom from near the surface in the case of juveniles to 732 m (2,402 ft), occasionally down to 1,420 m (4,660 ft), for the adults. They are said to eat jellyfishes, other fish, squid, and octopus, although recent catches show no squid beaks but large numbers of jellyfish. Ragfish are rarely seen and little is known about them.

Wikipedia contributors, Ragfish; see linked history · CC BY-SA 4.0 . Plain-text lead excerpt, at most 180 words; no infobox or later sections Retrieved 2026-10-05T02:30:22.506899+00:00. This reference remains separate from the taxonomic record.

Identity & source status

Scientific name

Icosteus aenigmaticus Lockington, 1880

Name authority

Lockington, 1880

Common name

ragfish

Rank

species

Accepted status

accepted

Kingdom

Animalia

Phylum

Chordata

Class

Teleostei

Order

Scombriformes

Family

Icosteidae

Genus

Icosteus

Extinction status

Not supplied by this source

Source habitat flags: Marine: yes · Freshwater: no · 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. orderScombriformes
11. familyIcosteidae Jordan & Gilbert, 1880
12. genusIcosteus Lockington, 1880
13. speciesIcosteus aenigmaticus Lockington, 1880

Close classified relatives

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

Browse 1 records assigned to Icosteidae.

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. Lockington, W. N. (1880). Description of a new genus and some new species of California fishes (Icosteus aenigmaticus and Osmerus attenuatus). Proceedings of the United States National Museum, v. 3 (no. 123): 63–68. https://doi.org/10.5479/si.00963801.123.63 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:3PB7H. Classification follows source parent identifiers. English common names may vary by region.