[8] Ceratiidae are characterised by having elongated, laterally compressed and relatively large bodies, compared to other deep-sea anglerfishes.

The posterior of the very long pterygiophore of the illicium sticks out from the midline of the body and is retractable within a furrow which runs the length of the upper part of the head.

The rear end of this furrow forms a cylindrical tube in the skin which projects in front of the modified first dorsal fin rays, or caruncles.

When they are free-swimming the males have naked, unpigmented skin but when they join with a female to become sexually parasitic they develop dark pigmentation and a covering of spinules.

The second dorsal spine in larval and juvenile females has a bioluminescent gland at its tip that is becomes reduced and hidden beneath the skin immediately to the rear of the base of the illicium in adults.

The males use their highly developed sensory organs to actively search for females which they attach themselves to using the denticular teeth on the tips of the jaws and becoming sexual parasites, fusing their tissue and blood vessels.