I bought a lobster from my lfs. He had it in a tank with nothing besides sand and a bunch of emeralds. Within a week all 3 of my emeralds are dead. I noticed him munching on them in his cave and then the next day the bodies were shoved out. Now my lfs told me he wouldnt harm them and the lobster was in with a bunch of em. But I know their territorial and since adding it all 3 of my emealds just died within days of eachother. Any advice appreciated.