Photostylus is a monospecific genus of deepwater maine ray-finned fish belonging to the family Alepocephalidae, the slickheads. The only species in the genus is Photostylus pycnopterus, the starry smooth-head, a species found in all oceans at depths of from 1,000 metres (3,300 ft) to 2,000 metres (6,600 ft). This species grows to a length of 11 centimetres (4.3 in) SL.