The yellow tang (Zebrasoma flavescens) belongs to the family Acanthuridae, which includes the surgeonfishes and the other tangs. Yellow tangs are good fish for beginning saltwater aquarists because they are able to tolerate fluctuating water conditions better than other tangs or surgeonfishes (up to a certain point).
Their natural habitat is the Indo-Pacific. They are frequently found in groups in shallow water off the coast of the Hawaiian Islands. This is where most of the yellow tangs sold in pet stores are from. In their natural environment they are reef fish that feed on algae and occasionally on small crustaceans.
Adult tangs reach a size of between 6-8 inches (15-20 cm). They are excellent fish for reef tanks and a small group of them may be kept in the same tank, providing your tank is large, you have plenty of live rock for hiding places, and they are introduced to the tank at the same time. In smaller tanks they are best kept as a single species as they tend to be territorial. They often don't tolerate the presence of other species of tangs or surgeonfishes in their tanks. Yellow tangs will tolerate other fish species that are not tangs or surgeonfish, however.
Yellow tangs are herbivores and must be provided with a diet of marine algae and plant-based marine fish food in order for them to survive and remain healthy in captivity. They will eat thawed frozen and dry food for herbivores and you should supplement their diet with living algae in your aquarium. They will also eat meaty marine foods, but most of their diet should be plant-based. It is a good idea to supplement their diet with dried seaweed (sushi nori).
You must feed them the appropriate diet for herbivores or their brilliant yellow color will fade and they will develop health problems.
Males and females look identical in appearance. They are not known to breed in captivity.
Yellow tangs can usually be obtained for about $25-50 dollars each, with smaller fish being less expensive.