Mine ate frozen Hikari mysis within a week (yeah I know, don't rub it in) but then it sat on a Rhodactis mushroom & was too stupid to move when it closed up over him. One moment healthy & happy, 5 minutes later the mushroom opens & the suffocated mandarin's still sitting on it.
I'll get another later but I always try to keep a healthy population of live mysis & pods running around in my tanks anyways, just in case I fall for another beauty at a LFS.
Anthony
PS. the mandarin has been the only fish stupid enough to fall victim to the slow closing "purse" of my Rhodactis shrooms.