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 1000m (3,000feet) to 2000m (7,000feet). This species grows to a length of 11cm (04inches) SL.