If you ever had an opportunity to snorkel around coral reefs, you’ll probably have seen some parrotfish. There are many different species called parrotfish, but most are a couple of feet long and colored in vivid blue and green. What really sets them apart from other types of fish is their pronounced beak, just like a parrot’s.
What about the Parrotfish?
As mentioned, it likes to hang out along coral reefs, simply for finding some tasty food, such as algae growing on the coral limestone. The corals themselves are somewhat averse to being eaten alive. So, when a predator comes along, they’ll quickly retreat into their coral-limestone-fortified housings. But that’s no problem for the parrotfish. While they mostly graze on the algae, parrotfish don’t mind the occasional protein-rich dietary supplement of an actual live coral either.
Coral (stone part) is pure limestone, calcium carbonate in chemical terms. Another form of naturally occurring pure limestone is marble.
Grazing the hard coral is tough on the teeth. If you don’t believe me, just try to chew some marble. With its heavy parrot-like beak though, the parrotfish can gnaw and break off the solid coral limestone to get to the softer parts it really is after. Any “limestone roughage” is simple spit out or excreted.
Reef and Atoll Builder
You may think the parrotfish’s influence on coral reefs to be destructive, but that is not so. In fact, the opposite is true. Preventing the inundation of coral reefs with algae and (indirectly) other species feeding on such, the parrotfish fulfills a vital function for the reef’s survival and growth. In effect, the parrotfish is a reef and atoll builder by enabling the corals to flourish.
When the parrotfish breaks down some coral stone into smaller pieces, it replenishes the supply of limestone sand at the bottom. With the next big storm, much of that will become suspended in the water column, carried along, and re-deposited further up the shore. That is how atolls have been growing for thousands of years. That is how the hundreds of atolls in the Pacific and Indian Oceans have been built and that is why they are still growing.
So, next time you see a parrotfish, give him a round of applause.
