Ctenopteryx sicula, a bathypelagic loliginid squid?

Ctenopteryx sicula (Verany, 1851) is an open-eyed, deep-water squid, and as such has traditionally been classified in the suborder Oegopsida (family Ctenopterygidae) along with other families of squid exhibiting these characteristics. C. sicula however displays numerous morphological features, including fused axons in the giant nerve fiber system and accessory nidamental glands, found otherwise only within members of the myopsid families Loliginidae and Pickfordiateuthidae. This has lead previous authors to suggest that Ctenopreryx species would be more appropriately placed in the suborder Myopsida. Here biochemical genetic evidence is presented which indicates that C. sicula is more closely related to several loliginid species than to species of the oegopsid families Histioteuthidae, Ommastrephidae, and Enoploteuthidae. These data, in conjunction with new data on comparative beak morphology, also suggest that C. sicula should be considered an oceanic myopsid species.