That's a lovely shell. I love these guys. I never try to control the population with mine, but I suspect my bristlenoses like to roll the biggest ones and eat them. Somebody in the tank is - the littlest ones are fine, but I'm always finding big shells empty on the surface of the gravel, and between brochis, rasboras and the bristlenoses, the plecos are far and away the most aggressive fish in there. I may take you up on the offer just to vary my gene pool later on when the weather warms up (we're still having days in the 30's).