Interesting to see how the substrate is completely covered with upside-own jellyfishes except in the area than the tentacles of the Mediterranean tube anemone can reach!!
Yeah, cnidarians are "territorial" in a way, they do use their nematocysts to keep others at bay. In both aquariums and the wild corals and anemones have been seen to damage neighboring colonies that grow too close. Certain types are recognized as "aggressive", in the sense their tentacles punch a pretty powerful sting that recoils any would-be encroachers. It has been documented where over time an aggressive species has killed off a less potent neighbor simply by growing its direction and slowly killing off more and more tissue.
