Napoleon Fish is also the humphead wrasse is the largest living member of the family Labride, with males reaching 6 feet (2 m) in length, while females rarely exceed about 3 feet (1 m). It has thick, fleshy lips and a hump that forms on its head above the eyes, becoming more prominent as the fish ages. Males range from a bright electric blue to green, a purplish blue, or a relatively dull blue/green. Juveniles and females are red-orange above, and red-orange to white below. Some males grow very large, with one unconfirmed report of a Humphead Wrasse that was 7.75 feet (2.29 m) long and weighed 420 lbs (190.5 kg). An even larger specimen is described in Captain Jacques Y. Cousteau's "The Living Sea" as being "...twelve to fifteen feet long and seven to eight feet high." as was quoted by Dumas and Falco.
Ecology~
Adults are commonly found on steep coral reef slopes, channel slopes, and lagoon reefs in water 3 to 330 feet (1–100 m) deep. They are very opportunistic predators preying primarily on crustacean, molusks - particularly gastropods- fish, echinoderms. They are one of the few predators of toxic animals such as the sea here Aplysia and boxfish Ostraciidae and have even been reported preying on crown-of-thorns starfish. This species actively selects branching hard and soft corals and seagrasses at settlement. Juveniles tend to prefer a more cryptic existence in areas of dense branching corals, bushy macroalgae or seagrasses, while larger individuals and adults prefer to occupy limited home ranges in more open habitat on the edges of reefs, channels, and reef passes. The species is most often observed in solitary male-female pairs, or groups of two to seven individuals.
Reproduction~
Individuals become sexually mature at 5 to 7 years and females are known to live for around 30 years whereas males live a slightly shorter 25 years. Humphead wrasse are protogynous hermaphrodites, with some members of the population becoming male at approximately 9 years old. The factors that control the timing of sex change are not yet known. Adults move to the down-current end of the reef and form local spawning aggregations (they concentrate to spawn) at certain times of the year.
Behaviour~
Humphead wrasse spend most of their time feeding during the day. Adults are usually solitary, spending the day roaming the reef and returning to particular caves or ledges to rest at night.
In some areas they are very inquisitive, but in others where they are hunted they are very shy. In the Red sea it is a very curious fish, where the fish have been fed with boiled eggs. Nowadays it is forbidden to feed Napoleon wrasse with eggs due to the high level of cholesterol that were found in dead specimens in the area.
Life Cycle~
Napoleon wrasses are extremely long-lived, known to survive for at least 30 years, and take around 5 to 7 years to reach sexual maturity, meaning they are extremely slow to increase populations.Predation~
With the exception of large sharks, there are few predators could tackle an adult Napoleon wrasse. As with most other marine creatures, humans are their biggest threat.Distribution~
This species is found throughout the Indo-Pacific oceans, from the Red Sea and the coast of east Africa to the central Pacific, south from Japan to New Caledonia. It is very rare in South East Asia thanks to the Chinese restaurant trade and illegal fishing, but is very common in the Red Sea and the Maldives due to park ranger control.Habitat~
The Napoleon wrasse is mainly found on coral reef edges and drop-offs. Juveniles can be found among branching corals in shallow lagoons, while adults prefer the upper margins of clear lagoon pinnacles and steep coral reef slopes to a depth of at least 100 metres, but occasionally up to 160 metres deep.They move into shallow bays during the day to feed, and tend to move into deeper waters as they grow older and larger. Adults therefore, are more common offshore than inshore.
Feeding Habit~
Napoleon fish are carnivorous and eat during the day. They can be seen feasting on shellfish, other fish, sea stars, sea urchins and crabs, crushing the shells to get at the animal within. They also crush large chunks of dead coral rubble with peg-like teeth to feed on the burrowing mussels and worms.Napoleon wrasse are one of the few predators of toxic animals such as sea hares, boxfish and crown-of-thorns starfish, and are therefore an important part of the marine food chain in maintaining a balanced and healthy coral reef.
Another Information~
The humphead wrasse is long lived, but has a very slow breeding rate. Its numbers have declined due to a number of threats. Threats include:
- Intensive and species-specific removal in the live reef food fish trade.
- Spearfishing at night with SCUBA gear.
- Destructive fishing techniques, including sodium cyanide and dynamite
- Habitat loss and degradation.
- Juveniles being taken from the wild and raised or “cultured” in floating net cages until saleable size.
- A developing export market for juvenile humphead wrasse for the marine aquarium trade
- Lack of coordinated, consistent national and regional management.
- Illegal, unregulated, or unreported (IUU) fisheries.
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| A Humphead Wrasse |
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