I would have thought this is a number of individuals at various ages I'm afraid. The species appears to be the commonly kept Bubble-tip Anemone Entacmaea quadricolor.
@Prochilodus246 You may well be right: I thought this might be a clone with new individuals budding off from an original parent and I note that @Philipine eagle lists Malu anemone and bubble-up anemone on his species list for this tank in the current Antwerp thread, but have no expertise in this field, so I am in no position to comment further.
