Dd is very upset When she went to feed her fish one of them looked dead. It is breathing but it's fins or tail aren't moving, and it seems kind of flopped to one side. It was almost at the top of the tank but I moved it to another so I could clean them out, and it seems to have taken soem of the food. Back in the tank it's now on the bottom, still breathing, its eyes moving a bit. Is it too late?