Parrotfish are a group of 90-odd species found in coral reefs, seagrass beds and rocky areas around the world, with the highest diversity in Indo-Pacific waters. Their vibrant and eye-catching colors—shades of electric blues, greens, pinks and purples—are known to add to the beauty of coral reefs.
These industrious fish spend the majority of their lives cleaning coral reef systems by eating the algae and polyps that live on them.
This is a win-win-win for everyone involved: the corals stay clean and healthy, the reef fish enjoy a well-kept habitat, and the parrotfish remain well-fed.
These fish also munch on algae-covered rocks, equipped with some of the sturdiest teeth in the animal kingdom to handle the task. But the real surprise comes at the other end of their digestive system: after breaking down coral and algae, they excrete it as pearly white sand, helping to create the beautiful beaches we know and love.
A Single Parrotfish Can Have Up To 1,000 Teeth—Some Of The Strongest In The Animal Kingdom
If you think sharks land the most lethal bites in the marine world, think again. The teeth of a parrotfish are made of some of the hardest biominerals (materials produced by living organisms) to ever exist.
They are even tougher than wood, aluminum and glass. These fish possess up to 1,000 teeth, which are melded together like chain mail to form a parrot-like “beak” that chews away at corals and earns them their name.
The tensile strength (maximum load that a material can support without fracturing) of a parrotfish tooth at the surface where the bite lands is so high that it can withstand 530 tons of pressure per square inch. That’s like the weight of 88 elephants compressed into a single square inch.
The hardest known biomineral, though, is the tooth of a limpet or sea snail that also chew algae off of hard rocks. Expanding our knowledge of teeth possessed by limpets or parrotfish could help inspire advancements in manufacturing long-lasting materials like those used in construction, electronics or dental fillings.
The myriad teeth of parrotfish are present from their mouth all the way inside their digestive systems. They are inept at breaking down food so finely in a process called bioerosion, that the fish excrete actual sand.
A Single Parrotfish Poops Thousands Of Pounds Of Sand Into Our Beaches
A single fish can poop out hundreds to thousands of pounds of sand each year, and these make up a significant chunk of the pearly white sands found on Pacific beaches. A single heavybeak parrotfish can poop out more than 2,000 pounds of sand each year.
Some scientists estimate that as much as 70% of sand found on beaches in the Caribbean and Hawaii are produced by parrotfish.
Parrotfish species occur in a range of sizes, from as small as five inches to five feet in length. Some species like the queen parrotfish secrete enough mucus from their mouths to form a protective cocoon around themselves at night before sleeping.
This viscous cocoon helps conceal the fish’s scent from predators like moray eels. It also acts as a unique warning system, letting the fish know to flee when the cocoon is disturbed.
Some studies have ventured into the theory that the consumption of parrotfish could be leading to the decline of corals, but much evidence points to otherwise. The ecosystem services offered by parrotfish cannot be ignored—in areas like the south Pacific, where bumphead parrotfish are overfished, corals have become suffocated by seaweeds.
This is observed on many reefs around the world, and parrotfish populations are often declining in these parts too. Bumpheads are particularly vulnerable because of their ill-fated habit of sleeping in aggregations in shallow waters, where they become an easy catch for fisheries. They are eaten in many countries and sold under the false label of grouper, for which there is higher demand.
Such pressures have led to the local extinction of bumpheads in Guam and heavy depletion in other areas like the Solomon Islands.
Biodiversity loss is at an all time high with unpredictable climate change effects unfolding every day. Our interconnected oceans feel the effects in intense ways, with warming, acidification, hurricanes and sea level rise increasing in frequency. How anxious are you about climate change and how is it affecting you? Take this test to find out: Climate Change Worry Scale
