Animal
Humphead wrasse
The humphead wrasse is a huge, gentle reef fish. Big ones have a bump on their forehead and wavy lines on their face. It sleeps in a cave on the reef every night.
The humphead wrasse is the biggest fish in the wrasse family, up to about 2.3 meters long. Adults have thick lips, a forehead hump and wavy lines on the face. They eat shellfish, sea urchins and even toxic crown-of-thorns starfish, and many change from female to male. Too many have been caught, so it is endangered.
Cheilinus undulatus is the largest member of the wrasse family (Labridae), reaching about 2.3 meters and 190 kilograms. It is long-lived (at least 32 years), slow to mature and a protogynous hermaphrodite that changes from female to male. Heavy fishing for the live reef fish trade has caused steep declines, and the IUCN lists it as Endangered (assessed 2024, published 2025); it is also listed on CITES Appendix II.
Photo: R Vasconcellos, CC BY 4.0, via Wikimedia Commons
Meet the humphead wrasse
The humphead wrasse is a very big reef fish.
It is green and blue. Grown-ups have a big bump on their forehead. They have thick lips and wavy yellow lines on their face.
The humphead wrasse is a giant of the coral reef. It is the largest fish in the wrasse family, and the biggest can grow to about 2.3 meters long and weigh about 190 kilograms, heavier than two grown-up people.
Adults are green with a dark bar on each scale, and their blue-green heads are covered in wavy yellow lines. Two black lines run back from each eye. As they grow, adults develop a large hump on the forehead, which gives the fish its name, and they have big, thick lips.
Cheilinus undulatus is a ray-finned fish (class Actinopterygii) and, according to the Australian Museum, the largest species of the wrasse family, Labridae, growing to 2.3 meters and 190 kilograms; FishBase gives a common length of about 60 centimeters. The species name undulatus comes from the Latin for 'wavy'.
FishBase describes a deep body, prominent jaws and lips with two strong canine teeth at the front of each jaw, a rounded tail fin, and pointed dorsal and anal fins in adults. Adults have an olive to green body with a dark vertical bar on each scale, a blue-green head with irregular yellowish lines, two black lines behind each eye and a large forehead hump. Juveniles are paler, with dark scale bars and bold lines through the eyes.
Quick facts
- Group
- Fish
- Length
- 0.6 to 2.3 m
- Weight
- up to 190 kg
- Lifespan in the wild
- up to 32 years
Reef slopes from the Red Sea to the Pacific
Humphead wrasses live on coral reefs in warm seas.
Babies hide in coral and seagrass. Big grown-ups swim along the steep edges of the reef.
Humphead wrasses live in tropical seas from the western Indian Ocean and the Red Sea all the way to French Polynesia in the Pacific. They are usually found on healthy coral reefs, from about 2 to 100 meters deep.
Young fish live in coral-rich lagoons, especially among branching staghorn corals, and in seagrass beds and mangroves. Adults prefer the outer edge of the reef, where steep slopes and drop-offs meet the open sea.
The IUCN describes a range across tropical and subtropical waters from the western Indian Ocean, including the Red Sea, to French Polynesia, at 2 to 100 meters. It does not appear to occur in the Persian Gulf, on the mainland coasts of the Arabian Sea, on Australia's northwest coast west of Cape York, or in the Bay of Bengal (although the Australian Museum notes offshore reefs of northwestern Western Australia).
Small juveniles use seagrass, hard corals and soft corals; larger juveniles live in coral-rich lagoon reefs, especially staghorn Acropora thickets, seagrass beds and inshore mangroves. Adults are more common offshore, on steep outer reef slopes, drop-offs, channel slopes and reef passes. The species is naturally uncommon, typically fewer than 10 fish per hectare.
Its habitat
Where can you find this animal?
- Lives here naturally · Countries and seas named by a scientific source
- Sightings recorded · Records of wild sightings (GBIF)
Lives here naturally · Countries and seas named by a scientific source
Coral reefs from the Red Sea and western Indian Ocean to French Polynesia, at 2 to 100 meters. The IUCN also lists many islands too small to shade here, including the Maldives, Seychelles, Mauritius, Reunion, Comoros, Palau, Guam and French Polynesia. The fish lives only on reefs along the coasts of each place shown, and it is now rare in many of them.
Places: Australia, Brunei, Djibouti, Egypt, Eritrea, Fiji, India, Indonesia and 21 more places.
Source: iucn-red-list · checked October 2026
Sightings recorded · Records of wild sightings (GBIF)
Counts of GBIF records of wild observations (human and machine) and preserved specimens. Records include introduced populations, vagrants, escaped or released animals and misidentifications, so a country with records is not necessarily part of the native range.
Wild sightings have been recorded in Australia, Egypt, Indonesia, New Caledonia, Philippines, Fiji, Malaysia, Solomon Is. and 33 more places.
Source: gbif · checked October 2026
Range maps show where scientists say an animal lives, often country by country. An animal may live in only part of a country shown, and sightings records can include animals that wandered far from home.
Crunching shells and spiny food
Humphead wrasses eat shellfish, crabs and sea urchins.
They can even eat spiky starfish that other fish leave alone.
Humphead wrasses eat many kinds of animals: shellfish such as snails and clams, crabs and other crustaceans, sea urchins and small fish.
They are also one of the few predators of animals that are poisonous to most others, such as sea hares, boxfishes and crown-of-thorns starfish.
The diet includes molluscs, fishes, sea urchins, crustaceans and other invertebrates (IUCN; Australian Museum). FishBase notes that it is one of the few predators of toxic animals such as sea hares, boxfishes and crown-of-thorns starfish.
Adults rove across the reef by day and rest in caves and under ledges at night (FishBase). The jaws and lips are prominent, with two strong canine teeth at the front of each jaw.
Did you know?
Its name, undulatus, means wavy.
The scientific name undulatus comes from the Latin word for wavy, after the lines on its face and body.
The epithet undulatus is Latin for 'waved' or 'wavy' (Australian Museum).
Hump, lips and wavy lines
The big bump on its head is called a hump.
Its lips are thick and strong. Wavy yellow lines cover its face, like a maze.
The forehead hump grows as the fish gets older and bigger, so small fish do not have one. It also has thick lips and two strong teeth at the front of each jaw.
Every humphead wrasse has its own pattern of wavy lines. Divers can recognize the same fish visiting the same part of the reef for a long time, just from its markings.
In adults the head profile is straight to above the eye, then becomes convex as a large hump develops on the forehead that can protrude in front of the eye (FishBase). The jaws and lips are prominent, with two strong canines at the front of each jaw, and the tail fin is rounded.
The irregular head lines differ between individuals. The IUCN notes that individuals identifiable by their natural markings may be seen along the same stretch of reef for long periods, and many dive sites have their own 'resident' humphead wrasse. The fish photographed here was seen in the Red Sea; a much smaller fish swims beside its head.
From female to male
Humphead wrasses grow up very slowly.
Most start life as girls. Some turn into boys when they are big. Many fish meet together to lay eggs.
A humphead wrasse grows slowly. Females start to breed at about eight years old. Many of them later change into males, at about 12 years old and about 80 centimeters long. A humphead wrasse can live for at least 32 years.
To breed, groups of up to 150 fish gather at the edge of the reef, where it drops into deep water, often soon after high tide. They release eggs and sperm into the water. The tiny young drift for about 25 days before settling on a reef.
The species is a protogynous hermaphrodite: individuals mature as females, at 40 to 60 centimeters and about eight years, and many later change to males, at about 12 years and roughly 80 centimeters; small males are occasionally found (IUCN). Longevity is at least 32 years, giving a generation length of about 20 years.
Spawning seasons are long, and in some regions spawning happens year-round, almost daily, in aggregations on drop-offs where the reef meets open water, up to 2.5 hours after high tide. In Palau up to 150 fish gathered along the shelf edge, with about 6 to 10 females for every male. The pelagic larval phase lasts about 25 days.
A reef regular
Humphead wrasses often swim alone or in pairs.
Each night they sleep in the same cave. Divers love to visit them.
Humphead wrasses usually swim alone or in pairs, though small groups of three to seven are sometimes seen. The same fish is often seen on the same stretch of reef for a long time.
At night they sleep in holes and caves, often the same ones night after night. Some tagged females travel more widely, with home areas about 10 kilometers across.
Usually solitary or paired, sometimes in groups of 3 to 7. Home ranges are at least 1,000 square meters, and tagged fish in the Seychelles showed site fidelity lasting more than 500 days. In the Line Islands, tagged females had home ranges with a median longest dimension of 10.3 kilometers, the largest known among coral reef bony fishes; males and juveniles averaged 2.9 and 0.7 kilometers (IUCN).
Adults sleep in cavities and caves, regularly reusing the same places. The IUCN notes that this makes them predictable to find, which helps divers but also spear fishers at night.
Did you know?
Divers can tell one wrasse from another by its face.
Each humphead wrasse's wavy face pattern is different, so divers can recognize the same fish on the same reef again and again.
Natural markings allow individuals to be identified, and many dive sites have a 'resident' fish seen along the same reef for long periods (IUCN).
A gentle giant in trouble
There are fewer humphead wrasses than there used to be.
People catch too many of them. Now many places protect them, and they grow back where they are safe.
The humphead wrasse is endangered. Since the 1980s, many have been caught alive and sold as expensive food. Much of the catch is young fish, and some are grown bigger in cages before they are sold. Because these fish grow slowly and breed late, they cannot replace themselves quickly.
Where they are protected, in marine parks or places where fishing is controlled, humphead wrasses stay common. A growing number of countries protect them by law, some by banning their export, and their trade between countries is controlled by an agreement called CITES.
The IUCN assessed the humphead wrasse as Endangered (A2bcd+3bd; assessed 17 July 2024, published 2025; also EN in 2004, VU in 1996), inferring a decline of at least 50 percent over the past 34 years and a decreasing trend. Fishing for the live reef fish food trade, which expanded in Southeast Asia in the 1980s to supply Hong Kong and mainland China, is the main threat, especially capture of juveniles for grow-out in cages. Coral reef loss adds to it.
Its traits make it vulnerable: low natural density, late maturity, sex change, spawning aggregations and predictable sleeping sites. It remains abundant where effectively protected, such as in the Maldives and Tubbataha Reef. It is listed on CITES Appendix II, and the IUCN notes that Saudi Arabia banned its capture, trade and sale in 2023.
IUCN Red List
How is the humphead wrasse doing in the wild?
- Least Concern
- Near Threatened
- Vulnerable
- Endangered (this animal)
- Critically Endangered
- Extinct in the Wild
- Extinct
Endangered
At very high risk of disappearing from the wild.
See the IUCN Red List assessment · The IUCN Red List of Threatened Species 2022.2
Amazing facts
-
A humphead wrasse can eat boxfish, which most fish can't.
The humphead wrasse is one of the few animals that eats toxic creatures such as boxfishes, sea hares and crown-of-thorns starfish.
FishBase lists it among the few predators of toxic prey such as sea hares, boxfishes and crown-of-thorns starfish.
-
Divers can tell one wrasse from another by its face.
Each humphead wrasse's wavy face pattern is different, so divers can recognize the same fish on the same reef again and again.
Natural markings allow individuals to be identified, and many dive sites have a 'resident' fish seen along the same reef for long periods (IUCN).
-
Its name, undulatus, means wavy.
The scientific name undulatus comes from the Latin word for wavy, after the lines on its face and body.
The epithet undulatus is Latin for 'waved' or 'wavy' (Australian Museum).
-
Some females swim very far around their reef.
Tagged female humphead wrasses in the Line Islands had home areas about 10 kilometers across.
Tagged females in the Line Islands had a median longest home-range dimension of 10.3 kilometers, the largest known among coral reef bony fishes (IUCN, citing Weng et al. 2015).
Words to know
- wrasse
- a member of a large family of colorful reef fish
- hermaphrodite
- an animal that can be female and male, at the same time or at different times of its life
- spawning aggregation
- a gathering of many fish in one place to release eggs and sperm
- juvenile
- a young animal that is not yet grown up
- CITES
- an agreement between countries that controls trade in wild animals and plants
- endangered
- at risk of disappearing from the wild
Discovery challenge
-
What grows on a big humphead wrasse's head?
What feature gives the humphead wrasse its name?
Which adult feature is the humphead wrasse named for?
- A hump on the forehead
- A long horn
- A crown of feathers
Show the answer
A hump on the forehead
Big ones grow a large bump, or hump, on their forehead.
Adults develop a big hump on the forehead as they grow.
A large forehead hump that can protrude in front of the eye in adults.
-
Which spiky animal can a humphead wrasse eat?
Which toxic animal is the humphead wrasse one of the few predators of?
Which of these toxic prey does Cheilinus undulatus eat?
- Jellyfish
- Crown-of-thorns starfish
- Sea snakes
Show the answer
Crown-of-thorns starfish
It can eat crown-of-thorns starfish, which are spiky.
It is one of the few predators of crown-of-thorns starfish, sea hares and boxfishes.
FishBase lists crown-of-thorns starfish, sea hares and boxfishes among its toxic prey.
-
What can happen to a humphead wrasse when it is big?
What change happens to many humphead wrasses at about 12 years old?
What reproductive strategy does the humphead wrasse show?
- It grows legs
- It changes from female to male
- It moves into a river
Show the answer
It changes from female to male
Many start as girls and later become boys.
Many start breeding as females and change into males at about 12 years old.
Protogyny: individuals mature as females and many later change to males, at about 12 years and 80 cm.
-
Why are there fewer humphead wrasses now?
What is the main reason the humphead wrasse is endangered?
What is the primary threat to the humphead wrasse according to the IUCN?
- People catch too many of them
- The water is too cold
- Sharks eat all the babies
Show the answer
People catch too many of them
People caught too many of them to eat.
Many are caught, often as young fish, and sold as expensive food. They grow too slowly to keep up.
Exploitation, mainly for the live reef fish food trade and juvenile capture for grow-out, made worse by its slow life history.
Places where you might see it
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Watch
Country
Australia
Australia is a country and the smallest continent, surrounded by ocean in the Southern Hemisphere. Much of its middle is dry and flat, most people live near the coast, and its animals include kangaroos, koalas and the platypus, a mammal that lays eggs.
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Watch
Country
Indonesia
Indonesia is a country of about 17,500 islands in Southeast Asia, spread across the Equator between the Indian and Pacific oceans. It has more than 100 active volcanoes, rainforests full of wildlife, and about 286 million people (2025).
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Watch
Country
Egypt
Egypt is in the northeastern corner of Africa, and its Sinai Peninsula reaches into Asia. Almost all of it is desert, so most of its more than 100 million people live along the green banks of the Nile River, where one of the world's earliest civilizations grew.
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For parents & teachers
What children will learn
- Describe the humphead wrasse's adult features (hump, lips, patterns) and its varied diet.
- Explain that some fish change from female to male during their lives.
- Understand why slow-growing, long-lived animals are easily harmed by overfishing, and how protection helps.
Recommended ages: 3 to 17 · About 12 minutes
Talk about it
- Why might a fish that breeds late and lives long be hurt more by fishing than a fish that breeds young?
- How could divers who visit the same 'resident' wrasse help protect it?
- Why might catching young fish be especially harmful to a population?
Try at home or in class
- Measure 2.3 meters along the floor with a tape and lie down next to it: that is the biggest humphead wrasse.
- Draw your own fingerprint-like wavy pattern and compare it with a friend's, the way divers tell wrasses apart.
Key vocabulary: wrasse, hermaphrodite, spawning aggregation, juvenile, CITES, endangered
Where these facts come from
- The IUCN Red List of Threatened Species , International Union for Conservation of Nature (IUCN terms of use (no redistribution of Red List data or range maps))
- GBIF Backbone Taxonomy and GBIF Occurrence Search , Global Biodiversity Information Facility (CC0 1.0 (backbone); occurrence counts are facts derived from records under CC0, CC BY and CC BY-NC)
- Cheilinus undulatus (Humphead Wrasse), 2025 global assessment , IUCN Red List of Threatened Species
- Humphead Maori Wrasse, Cheilinus undulatus , Australian Museum
- Cheilinus undulatus, Humphead wrasse: species summary , FishBase
- Wikidata , Wikimedia Foundation (CC0 1.0)
- Wikimedia Commons , Wikimedia Foundation (Per file: Public domain, CC0, CC BY or CC BY-SA only (credited on each page))
Checked, not yet human-reviewed. Last updated October 28, 2026. Spotted a mistake? Tell us.