I believe that that sentence could be written from the point of view of the anemone. The situation is unique in that the species of anemone itself may not exist outside of the "captivity" of this species of crab. I could be wrong, but all farm animals and pets are still related to some species of animal outside of human captivity. The closest analog of which I can think is the avocado plant whose seeds, as far as we know, can only be spread via human intervention.
