The fanfin family, Caulophrynidae, was first proposed in 1896 by the American ichthyologists George Brown Goode and Tarleton Hoffman Bean.

[1] The 5th edition of Fishes of the World classifies the Caulophrynidae within the suborder Ceratioidei of the order Lophiiformes.

[3] However, molecular studies show that the familial relationships within the Ceratoidei are still to be fully resolved and Caulophrynidae may be the most basal taxon in the suborder.

Its use may date as far back as Aristotle and Cicero, who referred to anglerfishes as "fishing-frogs" and "sea-frogs", respectively, possibly because of their resemblance to frogs and toads.

The sensory cells of the lateral line system are at the tips of the filamentous rays of the dorsal and anal fins.

[2] The largest species of fanfin is Caulophryne polynema with a maximum published total length of 21 cm (8.3 in).

[8] Fanfins are found in the Atlantic, Indian and Pacific Oceans where they live in the bathypelagic zone.