Yes, they will split and leave a small amount of themselves on the rock that forms into a new shroom. You can also do what I have done and help them along in this process and divide them into quarters. I have a 10g tank I use with a lot of rubble rock and shells for them to attach to when they are healed. I do not have a lot of flow in this tank so that they can easily stick to something and heal, I have propogated 2 red mushrooms giving me 8, 1 blue giving me 3,(one piece died) and a green giving me 4 more greens. I have a Superman mushroom that has split twice on its own and now I have 3 of them. I was lucky and got this one as a free hitchiker on a piece of rock I bought and since there was only one I didn't want to chance it dying. To split them, know they are very slippery and you will need a new, freshly washed razor blade, then divide them into quarters. I usually do this on a paper plate or paper towel so I can keep them in one place as I cut them. Good luck if you choose to try it.