Around the world's oceans, you may see the odd flash of blue, pink and green gliding among coral reefs, which is likely to be the parrotfish. Known to change colours and gender throughout their lives, these toothy, rainbow fish can munch on coral faster than a Brit eating a roast. Read on for our favourite facts about parrotfish.
Origins of the name
Parrotfish belong to the family Scaridae and get their common name from their resemblance to land-based parrots, thanks to their unmistakable beaks and colourful patterns.
Different species
As we just mentioned, parrotfish are named for their vibrant, parrot-like colours and bird-like beaks. But here's a fun parrotfish fact: no two species look the same. The bumphead has a distinctive hump on its forehead; the stoplight sports a bright amber spot on its tail, and the scribbleface dazzles with oranges, greens and purples. Just like it's easy to understand where the common name of parrotfish comes from, it's easy to guess the name of each species you're spotting based on their physical attributes.
Strong teeth
Parrotfish have some of the strongest teeth in the world, made from a biomineral called fluorapatite, which is harder than silver or gold. With around 1,000 teeth arranged in 15 continuously growing rows, these teeth fuse together to form the beak-like structure (hence the name). An impressive fact about parrotfish is that their powerful beaks can withstand the weight of 88 elephants (or 530 tons of pressure if we're being scientific).
Eating preferences
These herbivorous reef fish love to munch on corals and algae that grow on the reef's rocks. Using their strong, beak-like teeth, they bite off chunks of stony corals. But it's not the hard coral skeleton they're after - it's the tiny coral polyps living on the surface that provide the real nourishment. As coral munchers, parrotfish also have a second set of teeth in their throats, called pharyngeal teeth, which further grind down coral.
Sand makers
When a parrotfish accidentally swallows coral (and then grinds it up with their second set of teeth) they make sand. Since they spend about 90 percent of their time munching on algae, they often swallow coral, which produces a lot of sandy waste. A big parrotfish can turn up to 800 pounds of coral into soft, white sand each year. A fun fact about parrotfish is that up to 70 percent of the white sand on some beaches in Hawaii and the Caribbean comes from the coral these fish grind up.
Loud munchers
And with these strong beaks, parrotfish do cause some noise. Although diving is relatively quiet, among the coral reefs, you'll often hear a group of parrotfish munching on the hard coral.
Fast munchers
Another of our favourite facts about parrotfish is the speed at which they can eat. These prolific eaters can coral crunch at a rate of 20 bites per minute.
Gender fluid
A parrotfish fact you may not know is that they are gender fluid, switching sexes throughout their lives. They start as females and can change into males as they grow. A dominant, colourful male will guard a group of smaller, less colourful females and handle all the fertilising. As these females grow bigger, they might turn into males themselves and compete for the top spot in the group. This remarkable process, called protogynous hermaphroditism, involves not only a change in sex but also a dramatic shift in their colour each time it happens - so while each species is unique, it's also hard to find identical parrotfish within each species.
Bedtime rituals
We may think that nighttime rituals are just for those climbing into bed, but some species of parrotfish have a very special ritual. They build a transparent cocoon of mucus secreted from glands in their gills. These cocoons have two safeguarding benefits. First, it protects the parrotfish from bed bugs - such as parasitic isopods - and, secondly, it helps to mask their smell, keeping them safe from moray eels and sharks while resting.
Dance beneath the moonlight
Romance isn't reserved for land-based lubbers. Under the gaze of a full moon, hundreds of male bumphead parrotfish gather in what's known as 'lek mating'. This is when males aggregate to woo females via dance and displays of physical power. The males will bash their heads together to show off their strength and protective abilities before dancing as the females glide by. If successful, together, the hundreds of males and females will release their sperm and eggs into the water for fertilisation to take place. And so then begins the new cycle of life for parrotfish, who will change colours and sex, munch on coral, and, in turn, create more white sand beaches for us to lounge on.
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