Yellow tangs are one of the most common fish in the marine aquarium trade.
In the wild yellow tangs mainly eat a vegetarian diet consisting mostly of algae. But they will eat small meaty seafood and many people who keep yellow tangs in captivity feed then almost exclusively meaty fish food ignoring the natural diet of the yellow tangs. This does no good to the tangs who tend to die prematurely if not provided with algae to graze on.
Yellow tangs (Zebrasoma flavescens), being sold in a pet store.
Yellow tangs do need space to swim so when it comes to keeping yellow tangs it is not so much a minimum number of gallons of your tank but the length of your tank that matters, the longer the better. Some advise not to keep a yellow tang at all in a tank that is less than 75 centimeters long.
People tend to argue a lot about the welfare of various tangs, just Google the phrase ‘tang police’ to get an idea. Unfortunately I have to agree that tangs are somewhat delicate. It might be because they are usually wild caught and suffer during transportation but sometimes they do have trouble establishing themselves in an aquarium.
I like to keep at least one tang in my marine tank for algae control — often one cannot even keep more than one because they fight with similar fish, although yellow tangs tend to be less aggressive than some others and tolerate living in a group of their own kind.
But I had problems with various tangs over the years — sometimes even an established tang can die for no obvious reason. In my experience if you get a yellow tangs when it is very small they tolerate living in an aquarium well, but other people’s experience may vary regarding what sized yellow tang is the best candidate to establish itself in a home marine aquarium.
Further Readings:
Yellow Tang on thereeftank.com.
Descriptions and articles about the Yellow Tang (Zebrasoma flavescens) on the Encyclopedia of Life.