I sure dorked that one. I used 1.5mm instead of 1.05mm as the pinhead radius (that's the sort of thing that happens whenever I write calculations on a wet cocktail napkin) so the SA is way off. It should be about 3,460,000 sq. microns. And from the amoeba page, other sources list upper size limits at 60 microns, still others at "several millimeters". So you could get about 1200 amoebae, or zero, respectively. Either way, there doesn't apper to be much room on the dance floor, especially if one of the big ones shows up.