<a href=showthread.php?s=&postid=11855757#post11855757 target=_blank>Originally posted</a> by philter4
The reason they are not common in the hobby is they are really hard to collect as adults, they don't hide, they just run from the collectors and in deeper water where a barrier net is effective they just swim over the top.
As for hardiness, they are very hardy once acclimated, but just like other tangs they can be ick magnets and do sometimes develope skin infections, but this is the exception, not the rule, they are usually very easy to keep healthy.
Color change is a result of dominance, I've collected 2 inch blue ones and 5 inch yellow ones, it just depends on how dominant the animal is in the habitat or tank. Once the change starts they go from bright yellow to a dull brownish purple quickly then they develope a bright purple blue but still have a yellow tail. At this point they look like a red sea purple tang. From this stage (IMO the best looking color phase) to full blue with blue tail can take several months.