(genus Icosteus aenigmaticus), marine fish, the single species in the family Icosteidae (order Perciformes). The ragfish is found throughout the North Pacific. The name refers to their floppy, limp bodies, which are considered flexible as a rag.

Ragfishes have a cartilaginous skeleton that is almost completely lacking in true bone. The fins lack spines; scales and pelvic fins are absent in the adults. In shape, ragfishes are compressed laterally. Their colour ranges from brownish yellow in the juveniles to deep brown in the adults. Ragfishes attain a length of 2 m (6.5 feet). Their diet consists of other fishes and squid.