"The triplewart seadevil, Cryptopsaras couesii, is a seadevil of the family Ceratiidae, found in all oceans, from the surface to 2,000 m. Its length is approximately 30 cm for females and 3 cm for males.

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Males are free swimming when young but before they mature these small fishes (about a tenth the size of the female) attach themselves permanently to the hind body of the female and become parasitic. Their blood supply becomes continuous with that of the female and most of the internal organs degenerate; in essence the male becomes an appendage to supply sperm when required."

- Wikipedia