The Rudderfish, Centrolophus niger, is a medusafish, the only member of the genus Centrolophus found in all tropical and temperate oceans of the world, at depths of from 164.04 to 3280.84 ft (50 to 1,000 m). Its length is from 23.62 to 59.06 in (60 to 150 cm).
The rudderfish is a moderately elongated blunt-headed fish with long low dorsal and anal fins and small pectoral and pelvic fins. The body is covered in small, soft, easily-shed scales.
Its color is a uniform dusky brown or black, and the fish is a midwater-living species.
Illustration by Dr Tony Ayling