Scientific Classification
KINGDOM: Animalia
PHYLUM: Chordata
CLASS: Actinopterygii
ORDER: Perciformes
FAMILY: Labridae
GENUS: Cheilinus
SPECIES: Cheilinus undulatus
Conservation Status
They are the largest members of the wrasse family, which comprises over 500 different species. Males can grow up to 6 feet long and weigh up to 400 pounds, while females are usually a bit smaller.
Perhaps the most noticeable feature of the humphead wrasse is their huge lips and the protruding hump found on the males’ head. The females and juveniles lack a large hump and are usually a bit smaller at around 3 feet long. Their colors range from vibrant blue-greens to a more purplish-blue color.
It is believed the hump is a signal to females how genetically healthy the male is. It’s similar to a lion’s mane or a buck’s antlers. However, the hump sported by the male humphead wrasse is not used for any sort of combat.
They feed on a variety of prey, but specialize in hard-bodied crustaceans like crabs, shrimp, and echinoderms like starfish and sea urchins. If they aren’t eating these aforementioned creatures, they will eat small fish.
For larger, hard-bodied prey they will pick them up and break them apart by bashing them against rocks using a side-to-side motion. Once they break them apart, they will consume them bit by bit. Otherwise, they try and swallow them whole with one gulp. In the video below, you can see how a napoleon wrasse deals with a stonefish much the same way they would a sea urchin.
Humphead wrasses provide a vital service to coral reefs by eating the crown-of-thorns starfish. These large, unusual echinoderms actually eat coral and damage the reefs. Therefore, having the humphead wrasse around is like having a guardian for an entire ecosystem.
Large predatory fish like humphead wrasses are usually slow reproducers. This mechanism probably evolved because they are one of the largest fish on the reef and very few natural predators regularly attack humphead wrasses. So to avoid overpopulation they reproduce at a slower rate because few animals ate them until the arrival of man.
Compare this to something like sardines, which are short-lived, small, and low on the food chain. They reach breeding age quickly, and swim in huge schools. All of these mechanisms are designed to deal with a life as a prey species. As a result, they need to replenish their population fast and can handle heavy predation.
Humphead wrasses are just the opposite. They reach sexual maturity at around 4-6 years of age and can live up to 50 years. They usually travel alone and have few natural enemies once they are full grown. This is why they cannot handle heavy fishing from man.
When it does come time to breed, they will form spawning groups at the edges of the coral reefs. In areas where they are not hunted, these groups can be seen in the hundreds and is a rare sightt. Their eggs are tiny, less than half a millimeter, and will float near the reefs and ultimately settle at the bottom until they are ready to hatch.
One interesting adaptation the humphead wrasse has is the ability for the females to completely transform into males. Known as protogynous hermaphroditism it is believed this may have evolved as a way to increase reproductive success when few males are around. It’s not yet known what conditions cause this transformation, but it may be a chemical change in the environment or from the fish themselves.
This transformation only happens to females that have reached around 9 years of age, and once they have made the change into a male, they cannot change back.
One of the most striking fish you may see while snorkeling or diving in a coral reef is the humphed wrasse. These gentle giants go by many names, some of which are the napoleoan fish, maori wrasse, or napoleaon wrasse.
Humphead wrasse are one of the top predators in a coral reef ecosystem, they usually travel alone but are sometimes spotted in male and female pairs or in small groups during spawning.
