Marine Wildlife Encyclopedia
Cuckoo Wrasse Labrus mixtus
The cuckoo wrasse is one of the most colorful fish in northern European waters. Large mature males (shown here) are a beautiful blue and orange, while females are pink with alternate black and white patches along the back. When they are 7–13 years old, some female cuckoo wrasse change color and sex and become fully functional males. These males are known as secondary males and spawn in pairs with females. The male excavates a nest and attracts the female with an elaborate swimming display. To further complicate matters, it has been found that a very few cuckoo wrasse are born male but have the female coloring. These males are known as primary males and their role in reproduction has not been fully ascertained.