Surgeonfish (mixed school)

Dense mixed schools of powder-blue, striped and convict surgeonfish sweep across the Acropora tables in tight formation, grazing algae from the coral substrate and keeping the reef surface clear for new coral settlement. Their scalpel-like tail spines are a defence against predators including trevally and reef sharks. Schools occasionally number in the hundreds, creating an immersive wall of movement at the reef crest.