British Wildlife Wiki

The Rock Cook (Centrolabrus exoletus) grows to a Max. of 15cm


Small dumpy wrasse, with it's small head and deep set body. The mouth is also small but highlighted by fleshy lips, and has a single row of small conical teeth. Dorsal fin is long and is composed of two joined sections. The first is composed of some 18 to 20 membrane bound spines, with the second more lobate fin comprising of 5 to 7 branched rays. The anal fin is approximately half the length of the first dorsal fin, and has 4 to 6 slender spines in it's anterior section, followed by 6 to 8 branched rays.The scales of the head and body are relatively large and well defined, with 33 to 37 running the length of the lateral line.

Colouration is typically that of a greenish brown on the back with a dusting of blue flecking, that fades towards the yellow / brown of the sides and off-white of the belly region. Males exhibit blue stripes on the lower region of the head, along with blue spotting / stippling on the margins of the dorsal and anal fins.The tail has a distinct dark submarginal crescent band across it, and bounded by two lighter regions, with the tail fringe sporting a blue border.


Spawns during May and into June/July, in a nest of fine algae in rock crevices. Age expectancy up to 8 years.


Favours shallow waters (2 to 25m), with weed beds or eel-grass, and over rocky substrates, where it is most commonly encountered. Tends to be locally distributed.


Eats a variety of crustaceans, such as amphipods and copepods, whilst also acting as a cleaner fish, and removing ectoparasites from other fish.


Found all around the U.K.


The Aquarium Project