[2] The rock cook is a small wrasse in which the adults range in length from 10–15 centimetres (3.9–5.9 in).

This species is normally reddish-brown above fading to yellowish-silver on the flanks and to pale silvery-white on the belly.

The males have iridescent blue streaks on their dorsal, anal and caudal fins as well as on their heads.

[4] The rock cook is found in the eastern Atlantic where it is endemic to European waters from Norway to Portugal.

[1] The female creates a nest from fine seaweeds in which she lays her eggs during the summer months.