Alepocephalidae

Slickheads, also known as nakedheads or smoothheads, are deep water fishes that belong to the family Alepocephalidae. They are most commonly found in the bathypelagic layer, which is approximately 3000m below the surface. They get their name from the lack of scales on their heads. Similarly, the scientific name is from the Greek ᾰ̓- (a-, "not"); λέπος (lepos, "scale"); and κεφαλή (kephalē, "head"). It has about 22 genera with ca. 96 species.

The only known fossil genus is Carpathichthys from the Early Oligocene of Poland, although an undescribed species of Bathyprion and several indeterminate taxa are also known from the same formation. Fossil otoliths are also known, dating to the Early Eocene.