The humphead wrasse is a colorful fish found in the Indo-Pacific region. It is the largest living member of the wrasse family; it goes by different names such as Māori wrasse, mameng, merer, Napoleon wrasse, Napoleon fish, and so mei. Scientists identified this fish as an ‘umbrella species’. That means it has a vital role in the local ecosystem. Due to its enormous size, sometimes it is called the “elephant of the coral reef”.
Body and Coloration: Their coloration ranges from dull to vibrant blue-green and sometimes even purple-tinted blue, with gold-ish patterns on their heads and two black lines behind their eyes. The upper bodies of females develop a reddish-orange color. They have thick lips and a hump on their forehead.
Small juveniles have silver bodies and can be easily identifiable from adults. The larger ones start developing a pale green hue. Juveniles do not grow the hump on their forehead until they reach adulthood.
Female Humphead Wrasse
Male Humphead Wrasse
Range and Distribution
The distribution of the humphead wrasse ranges from the Red Sea across the East African coast and the Central Pacific. They can be found in Japan, Melanesia, and U.S. Pacific territories like Guam.
Humphead Wrasse Habitat
Humphead Wrasse Range
Habitat
They inhabit the reefs of tropical water. Adults mainly live around the steep drop-offs and outer slopes, while juveniles live among the staghorn coral groves. These fish commit to a particular site and rarely ever leaves those areas.
Diet
Their diet consists of crustaceans, mollusks, sea urchins, small reef fish, and snails. They also consume crown-of-thorns starfish and even toxic animals like boxfishes, pufferfishes, and sea hares.
Behavior
These fish are diurnal, spending most of their day feeding, and at night they return to their caves for resting.
The adults are primarily solitary; however, sometimes, they can be found in male and female pairs.
Although these are not primarily migratory fish, they sometimes migrate within local territories.
Humphead Wrasse Fish
Humphead Wrasse Picture
Lifespan
The lifespan of a humphead wrasse reaches up to 30 years.
Adaptations
They have strong teeth that help pierce through their prey’s hard shells. Also, their thick lips make it easier for them to absorb the spines.
These fish are immune to toxins, in particular sea creatures, allowing them to eat toxic prey without harm.
Their body is structured in a way that helps them to move efficiently in the water; they mostly use their pectoral fins, only using caudal fins and the tail in need of sudden speed.
Mating and Reproduction
During the breeding season, up to 100 humphead wrasses gather to spawn. Females release the eggs into open water, and males fertilize the eggs. After fertilization, hatched larvae settle onto the ocean floor until they grow into a swimmable size and then reach the coral reef areas. They reach their reproductive maturity at 5-7 years old.
Napoleon Wrasse
Maori Wrasse
Predators
The predators of these fish include sharks and other larger reef fish.
Conservation Status
The humphead wrasse is “Endangered” or “EN” according to the Red List of Threatened Species of the IUCN. It was also added to CITES Appendix II.
Their population has decreased by more than 50% due to degradation, climate change effects, habitat loss, illegal overfishing, and spearfishing along reefs.
