Ceratioidei

a suborder of fishes of the order Lophiiformes (Pediculati). The body is inflated; the skin is black and scaleless and is covered with small spines in a few species. Ventral fins are absent. There are ten families, including approximately 120 species. Distributed from Greenland to the subantarctic, the fish live mainly in depths of 1,500–3,000 m and reproduce only in warm waters, from 40° N lat. to 35° S lat. The USSR has three species in seas of the Far East and four in the ocean near the Kuril Islands.

Sexual dimorphism is marked in the Ceratioidei. The females, which generally measure 5–20 cm in length (in some species up to 120 cm), are many times larger than the males and are predators; the anterior ray of the dorsal fin has evolved as a “fishing rod” with a “lure” on the tip. The body length of males is 1.4–4.6 cm. In representatives of six families the males are free-living and feed on small crustaceans. In representatives of the remaining four families the males attach themselves to females and become sperm-producing appendages that feed upon the female by means of the fusion of the blood vessels of the two fish. As many as three males may parasitize a female.