(class Osteichthyes, subclass Actinopterygii)
An order of marine fish of widely differing shape and form, ranging from the deep-bodied Lamprididae (opah) to the eel-like Regalecidae (oarfish). They have a unique type of protrusible jaw, fins without true spines, and a rather small mouth. Some families (e.g. Mirapinnidae) have also been placed in another order.
Subjects: Zoology and Animal Sciences.