Why do parrotfish crunch coral reefs?
Quick Answer
Parrotfish bite coral to scrape off algae and tiny organisms growing on the reef. The coral skeleton passes through their guts and is often expelled as sand.
The Full Story
Parrotfish do not eat coral because they need the coral skeleton itself; they scrape algae and microscopic growth off the reef surface with their beak-like teeth. In the process, they grind up bits of limestone coral and other carbonate material. Much of that material is excreted as fine sand, which helps create and maintain tropical beaches and reef sediments. Large parrotfish can produce impressive amounts of sand over time, making them important reef ecosystem engineers. Their feeding also helps keep algae from overgrowing coral, which can support reef health.
Key Facts
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Suggested video title for this topic:
"The fish that makes sand from coral—how does that work?"