Ragfish

Taxobox
name = Ragfish


image_width = 200px
image_caption = Juvenile (top) and adult
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
ordo = Perciformes
familia = Icosteidae
genus = "Icosteus"
species = "I. aenigmaticus"
binomial = "Icosteus aenigmaticus"
binomial_authority = Lockington, 1880The ragfish, "Icosteus aenigmaticus" (Lockington, 1880), is an odd ray-finned fish of the northern Pacific Ocean; although a perciform, 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, and some authorities place it into its own order Icosteiformes.

The ragfish body is scaleless and limp, both because of the cartilaginous skeleton, as well as 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 two meters.

Ragfishes are found in deeper waters out to sea, and are said to eat other fish, squid, and octopus, although recent catches show no squid beaks but large amounts of jellyfish.

The larvae make a remarkable transformation as they mature; the caudal fin shrinks, and the pelvic fins disappear.

References

*

External links

* [http://www.fishbase.org/Summary/SpeciesSummary.cfm?id=3929 FishBase info for ragfish]
* [http://www.calacademy.org/research/ichthyology/annotated/checklists/Icosteidae.pdf Cal Academy checklist report, September 2003 (PDF)]