# Ragfish

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> Markdown URL: https://mediated.wiki/source/Ragfish.md
> Source: https://en.wikipedia.org/wiki/Ragfish
> Source revision: 1256606102
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

{{Short description|Species of ray-finned fish}}
{{Speciesbox
| image = ragfish.png
| image_caption = Juvenile (top) and adult
| display_parents = 4
| grandparent_authority = [D. S. Jordan](/source/David_Starr_Jordan) & [C. H. Gilbert](/source/Charles_Henry_Gilbert), 1880
| genus = Icosteus
| parent_authority = [Lockington](/source/William_Neale_Lockington), 1880
| species = aenigmaticus
| authority = [Lockington](/source/William_Neale_Lockington), 1880
| synonyms =
Genus:
* ''Acrotus'' <small>T. H. Bean, 1888</small>
* ''Schedophilopsis'' <small>Steindachner, 1881</small>
Species:
* ''Schedophilopsis spinosus'' <small>Steindachner, 1881</small>
* ''Acrotus willoughbyi'' <small>T. H. Bean, 1888</small>
}}

The '''ragfish''' (''Icosteus aenigmaticus'') is a [ray-finned fish](/source/ray-finned_fish) of the northern [Pacific Ocean](/source/Pacific_Ocean); although classified as a [bony fish](/source/bony_fish), its [skeleton](/source/skeleton) is mostly [cartilage](/source/cartilage), and the [larva](/source/larva)e have [pelvic fin](/source/pelvic_fin)s that disappear as they mature. It is the sole member of the family '''Icosteidae''' within the order [Scombriformes](/source/Scombriformes).<ref name="FishBase" />

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](/source/dorsal_fin) and [anal fin](/source/anal_fin)s 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 {{convert|732|m|ft|abbr=on}}, occasionally down to {{convert|1420|m|ft|abbr=on}}, for the adults.  They are said to eat jellyfishes, other fish, [squid](/source/squid), and [octopus](/source/octopus),<ref name="FishBase">{{FishBase |genus= Icosteus|species= aenigmaticus| month = October | year = 2024}}</ref> although recent catches show no squid beaks but large numbers of [jellyfish](/source/jellyfish). Ragfish are rarely seen and little is known about them.<ref>{{Cite web|url=http://www.adn.com/article/20160107/rare-deep-sea-fish-washes-ashore-gustavus|title = Rare deep-sea fish washes ashore in Gustavus}}</ref>

The larvae make a remarkable transformation as they mature; the [dorsal fin](/source/dorsal_fin) and [anal fin](/source/anal_fin) both shrink, and the pelvic fins disappear.

Formerly, adult ragfishes were considered to be a different species, known then as ''Acrotus willoughbyi''.<ref>{{cite web |url=http://www.photolib.noaa.gov/htmls/figb0639.htm |title=NOAA Photo Library |website=www.photolib.noaa.gov |url-status=dead |archive-url=https://web.archive.org/web/20080806060720/http://www.photolib.noaa.gov/htmls/figb0639.htm |archive-date=2008-08-06}} </ref>

==References==
{{Reflist}}

==External links==
*[https://web.archive.org/web/20040521205938/http://www.calacademy.org/research/Ichthyology/annotated/checklists/Icosteidae.pdf Cal Academy checklist report, September 2003 (PDF)]

{{Taxonbar|from1=Q133707|from2=Q17141214|from3=Q17141212|from4=Q106548585}}

Category:Scombriformes
Category:Fish of the North Pacific
Category:Fish described in 1880

{{Scombroidei-stub}}

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Adapted from the Wikipedia article [Ragfish](https://en.wikipedia.org/wiki/Ragfish) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Ragfish?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.