I'm setting up a new 5g reef. This past weekend I added 3 red legged, 1 blue legged and 2 astrea snails. The guy at the shop also gave me 2 empty shells that the hermits could move into later when they got bigger. Today, I noticed something in one of those empty shells... it's sitting on the front of the shell it came from. Since I'm new to all of this, I'm guessing this is another astrea snail... but I'm not sure. Anyone have a better idea?