Lieutenant tang

The lieutenant tang is a surgeonfish in the family Acanthuridae, found in the Indian Ocean and adjacent western Pacific reefs. It inhabits clear coastal and outer reef zones. Adults are dark brown to olive with fine wavy vertical lines and often display a pale patch and darker markings around the head; the sharp caudal spines typical of tangs are present at the base of the tail. Coloration can shift with mood. It is semi-aggressive, especially toward other tangs, and needs a large aquarium with abundant swimming space and live rock for grazing and refuge. Primarily herbivorous, it should be offered marine algae and dried seaweed alongside prepared foods to maintain health. It is best kept as the sole tang in most systems and suits intermediate to advanced marine keepers.