During its development, the giant wrasse will change sex. We then speak of successive hermaphroditism. All giant wrasses are born female and reach their sexual majority around the age of 7. Some individuals would then become males around their fifteenth year. Their appearance changes: they drop the red-orange of their scales for a more or less bright blue-green color, and their legendary bump develops and becomes more pronounced with age.
Napoleon plays an important role in the ecosystem of coral species. Indeed, giant wrasses are one of the few animals that can feed on the purple acanthaster or Christ's crown (Acanthaster planci), an invasive starfish species whose diet consists almost exclusively of coral. It also feeds on mollusks, crustaceans and other poisonous species such as box fish or sea hares.
Now protected by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (1973), its population is estimated to have halved over the past 30 years. Its fishing is prohibited in many countries, but it is not always controllable, and this animal is still abundantly fished in the Philippines, Indonesia and Thailand.
In addition to their pretty colors, giant wrasses have the misfortune of being very tasty and are considered a luxury treat in Hong Kong where some businessmen are willing to pay 2000 USD to wow the gallery by eating a pair of lips!
No more than other species for that matter ... Tourism poses a certain risk for the Napoleon wrasse population. At some tourist hot-spots, animals are baited by food thrown by boats, in other places, dive guides feed them hard-boiled eggs to amuse tourists.
The fish become dependent on these baits and no longer distrust boats or humans.