Blue tang

Photo: Sara K. · CC BY-NC

Blue tangs are surgeonfish equipped with a razor-sharp scalpel near the tail used in defence and territory disputes. They are important herbivores on Caribbean reefs, grazing filamentous algae from coral surfaces and helping prevent algal overgrowth that would otherwise smother corals. Large feeding aggregations of blue tang travel across the reef in sweeping formations, cropping algae methodically. Their abundance is a strong indicator of reef ecosystem health. They are not commercially fished in the region and remain common on protected reefs.