Who is what here?

[THE_MAD_REEFER]

I got the first nem about two months ago and it was the size of a quarter. I got the second (front in the pic of both) nem after that and it was the same size(about four inches across).
I would like to know the difference between the two. Like how the one has tripled in size and the other stayed the same but both look great. I feed them both at the same time and they are under the same light. The small one has awesome white specks throughout and the big one in front is solid color. Are they different species?

 

[D-Nak]

They're both BTAs so they're the same species, but like many anemones, they can behave differently even though the conditions are exactly the the same.