High Quality Content by WIKIPEDIA articles! The 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.