The Maori wrasse is a favourite among many visitors in the Whitsundays as well as the crew on board Whitsunday Catamarans. Maori wrasse are a magnificent and truly awesome fish that can be as big snorkellers and divers themselves! Swimming with big wrasses will be the highlight of your trip in the Whitsundays, as they are found in many of the reefs and bays visited by Whitsunday Catamarans.
Maori wrasse are also known as the Napoleon wrasse or humphead wrasse, due to a large bubble-like hump on the top of the males heads.
Maori wrasse are the largest of the wrasses having a length up to 229 cm (7.5 feet) and weighing up to 191 kg (420 pounds). The females come in drab shades of gray, red or brown, whereas the males are a light green to aqua with squiggly pattern on the head and front of body. They are more easily recognized by the males as they are easily identified and have such a striking appearance. These fish are easy to spot on the reef, not only because of their size, but also because the adult males develop a bulky bump on the forehead and have big plump lips. A pair of spiky teeth stick out of the mouth.
Living alone or sometimes in pairs, Maori wrasse live on lagoon reefs and steep outer reef slopes at depths of 1 to 60 m (3 to 200 feet). Diurnal or active during the day, this wrasse can be seen roving the reef. At night, the Maori wrasse heads home to rest in a reef cave or under a ledge. If chased after by a predator, this fish will dive into its resting place for safety.
It isn’t easy for prey can’t hide inside the crevices from Maori wrasse. This wrasse can jut its jaws in front of its snout, allowing the fish to pull prey out of reef holes and crevices, with a secure grip. This big fish also hunts concealed prey by biting off the things they’re hiding under like coral branches and tables, or blowing powerful jets of water out its mouth at the sand, uncovering any hidden creatures. If an escaping prey dives under a rock on the reef frantically searching for safety, the Maori wrasse turns over the hideaway with its powerful jaws.
The humphead mainly feeds on creatures most other fish won’t touch. Besides eating clams, snails, shrimp, crabs, sea stars, brittle stars and fish, this large wrasse eats dangerous or toxic animals like sea urchins, the crown-of-thorns sea star and boxfish.
Wrasses start their lives either as a male or a female, just like any other fish. But they can also change sex. These fish are protogynous hermaphrodites, which means they can start their life as a female and then change to the male. Wrasses are born with both male and female sex organs. After wrasses become adults, they are called initial phase males or females. Those that were born male will always remain as an initial phase male and will never have a chance to be a dominant male. Some of the adult females will change into males. These males and the remaining females are also called initial phase wrasses. But some of the larger females will become supermales. This most often happens when a supermale dies. The supermale is larger than all the other males and has distinct colors and patterns on its skin. This coloration attracts the females to the supermale.
Sex change in wrasses ensures there will always be a male to reproduce with all the females. The few supermale wrasses on the reef sport brilliant hues to attract all those females. Initial phase males are different from the supermales. When courting the females, the color of all the males will actually become brighter and more brilliant. Terminal phase males breed with a harem or a small group of females.
The supermale is territorial which means it protects a certain area and the females there too. Wrasses are pelagic spawners, which means they gather in groups in areas where the fertilized eggs will be taken by the currents. The eggs float in the epipelagic zone or the zone in the open ocean near the surface. Here the eggs hatch out and the larvae float along until they reach a certain size. After they are large enough, the young wrasses drop down and join the other reef creatures.