JennM;945870 wrote: Linckias are sensitive. If anyone along the chain of custody (before you got it) didn't acclimate it properly, it will disintegrate.
The trickiest part is acclimating after a long shipping period. Easier if it comes home from a local place, in a short amount of time.
Your best bet in either case is to check the specific gravity it came in before you start acclimating (this applies to anything, really). If it has been in a bag 24 hours or more, pH will drop and once you open the bag, chemical reactions happen quickly and there's a delicate balance between getting it out of gross water quickly enough, but not so quickly that you shock it with a fast specific gravity change (or pH - but pH will be low in old bag water).
If acclimated properly to a tank with stable parameters, they can and will live for many years.
Jenn