From what I understand, the tiny ones don't do well, but when you move up to the 2" to 3" + they get a whole lot hardier. I just got one last week from SWF and he hid for about 3 days, had a hollow belly. I was a little worried there for a while, but now he's out dashing around the tank having a grand time and the belly is getting nice a full. I have tons of algae in my tank so the saddle bar is open!