I had a 55 gal. tank that someone gave me, and it was late fall and I wasn't going to set it up until the following spring. I put about 5 inches of water in it so it would not dry out. It had gravel in it, as it was set up right before I received it. I had a cup with a half dozen baby shrimp in it that I had floating in there while I was cleaning my other tanks and was going to put them in one of the other tanks. Anyway some how I got side tracked and forgot about them. The next day when I went into fish room / furnace / laundry room in the basement, I could see the cup had sunk, but didn't see any cherry shrimp anywhere. There was no light on the tank, and no heater. I checked for them for next couple of weeks and put a little food in there. After three weeks, I gave up. The following spring, about four months later I was setting the tank up, which know only had a few inches of water, and to my surprise here the shrimp were. All alive and a couple where huge (over a inch and dark red). So these were some hardy little shrimp and a complete surprise.