The Yellow Tang, Zebrasoma flavescens, is a flat, oval-bodied surgeonfish carrying a saturated lemon-yellow coloration across the entire body and fins. That color is not static: at night, or when the fish is stressed, it fades to a duller grayish or olive tone, a normal response rather than a sign of disease. The species is native to Pacific coral reefs and ranges toward Japan, with the largest historical populations found off the western coast of Hawaii's Big Island near Kona. Adults occupy coral-rich lagoon and seaward reefs at roughly 6 to 150 feet, living benthopelagically over rock and coral either singly or in loose groups and schools. Wild adults reach about 8 inches, while aquarium specimens frequently top out nearer 6 to 7 inches.

Plan on a minimum of 100 gallons for a single adult, and understand that open horizontal swimming distance matters as much as raw volume. Systems in the 100 to 150 gallon range serve this fish far better over the long term. The aquarium should be mature and well filtered before a tang is introduced. Build generous live rock along the back and sides to supply grazing surfaces and two or three overhangs or caves for nighttime shelter, while leaving 40 to 50 percent of the footprint open for continuous swimming. Strong, consistent flow from powerheads or wavemakers mimics the reef currents this species evolved in. Keep one Yellow Tang per system unless the tank is 150 gallons or larger and multiple juveniles are introduced together, and avoid combining it with tangs of similar body shape or coloring in smaller setups.

Care Level is Moderate, driven largely by the dietary discipline and swimming space this fish demands rather than by any fragility in the aquascape or aquarium hardware.