I just started an aquarium a little over a week ago. I had 5 bluegills and a crappie minnow. The bluegills ranged in size from about one 3in, two 2in, and two about 1in. The crappie is about 2 in. After a week, i have had the two 1in bluegills and one 2in bluegill disappear from the aquarium without a trace. I checked the filter the gravel, everything. There is no possible way for anything outside the aqaurium to have gotten into it without me knowing. Is it possible that the other fish ate them? I'm completely baffled.