reference thread: extremely difficult fish

[hobogato]

this will be a running list of the fish we (maast members) believe are fish that require extremely specialized care and attention.

if you would like to add a fish to this list, please post it here along with why (personal experience) it should be included.

other things that would be helpful:

pics
how big was it when purchased?
how long have you had it?
what are its food requirements?
what other organisms is it compatible/incompatible with?
anything else you can think of