Blue Tang

About

The blue surgeonfish (Acanthurus coeruleus) is one of the most recognizable tangs in the Western Atlantic, ranging from the waters off New York and Bermuda all the way down through the Gulf of Mexico and Brazil, with a separate population around Ascension Island in the Eastern Atlantic. Adults are a deep, uniform blue-violet, but juveniles wear a bright yellow that slowly gives way to blue as they mature. A transformation that can genuinely confuse newer keepers who don't know what to expect. In the wild, this species turns up on coral reefs, rocky inshore areas, and seagrass beds, usually moving around in small groups during daylight hours. One of the more remarkable things about this fish is its documented behavior at the Fernando de Noronha Archipelago, where juveniles set up cleaning stations alongside other reef fish and actually service green sea turtles. Picking parasites and shed skin from their flippers, heads, and tails. In the aquarium, the blue surgeonfish is a dedicated herbivore and needs consistent access to algae and plant-based foods to stay healthy. Like all surgeonfish, it carries a sharp caudal spine that can cause a nasty cut if you're not careful during handling or net work. Given its adult size, it needs a genuinely large, well-established reef system and some open water to swim.