The longfin smooth-head is pale brown to black in colour; its name derives from its anal fin, which has a long base and 35–39 finrays. Its maximum length is 34 centimetres (13 in).[6] They grow rapidly from infancy; few juveniles of intermediate size are found.[7]
Habitat
The longfin smooth-head lives in the temperate and tropical Atlantic Ocean, and in the Gulf of Mexico;[8][9][10] it is bathypelagic, living at depths of 800–2,200 m (2,600–7,200 ft), being most common at 1,200–1,800 m (3,900–5,900 ft).[6]
Behaviour
The longfin smooth-head lays large eggs, up to 6 mm (0.24 in) in diameter, and are believed to be buried in redds, similar to how the Atlantic salmon buries its eggs.[11][12] A detritivore, the longfin smooth-head is recorded to ingest sediment from the seafloor, taking up with it microfauna such as foraminiferans.[13][14]
