So this actually happened by accident I had ordered some coral and in my order I had a Duncan long story short end up sending me another one of my orders again by accident and told me to keep it so I put the Duncan next to each other. Both started off at one head I’ve had them for about six months now and they have grown exponentially, but I have noticed something. They’re two different types of Duncan. One seems to be a single head just gets bigger with one head and the other has one big head and three medium size heads growing at the same time on it both placed within 2-3 inches of each other at the same level on the same rock and I’ve noticed that the one with the singlehead has gotten wider and has not grown up without any additional heads it’s definitely wider than the multi head Duncan also the tentacles on it are different. The singlehead one has oval shaped tentacles while the other one has normal ones also there’s a huge size difference height and disk size the branching Duncan is about the size of a quarter maybe a little bigger while the other one is about the size of a 50 Cent piece but the branching one is about a inch to inch and a half taller than the other lmk if you experience any like this as well