TeeVee thanks for the links.. did some poking around and these conches are certainly NOT Strombus Gigas. Searched around some of the other reef boards, and was able to id these conches as Melonga Corona. A species of Carnivorus snails
They have'nt done anything yet... but Im watching em! still not a bad deal for $ 2.65.. but I think they are destined for the DSB sump!