I can't find it now but there was a thread along the lines of what do you most regret having done, or something like that. Yellow Tangs came up a lot.
IMHO
*They are very easy to stress out
*Get massive parasite infestations every time you look crosseyed at them
*Their temperment can be aywhere from whipped puppy to serial killer.
*lfs resorts to feeding a diet of live brine shrimp, all though they look well fed, they're malnurished.
*Less than one out of every hundred that live long enough to get to a store live more than a year after that.