I just picked up some Otocinclus catfish at Exotic. They had 2 tanks with them in it, one with just a few, and one with maybe 50 of them. When I asked for them the clerk told me the tank with 50 or so had fish that were delivered yesterday -at least 6 dead ones were in there, plus a few who looked distressed. He recommended not getting any of those, but to get the few in the other tank, over a week in the store.
I really appreciated this, because I hadn't even seen the tank with the few in it and was expecting to have to watch carefully so I wouldn't be getting near dead ones. Apparently there is a high mortality rate on Otos when they first arrive at the store, something I have read here before. Three cheers for Exotic!