How do sea anemones compete with other anemones for space?

Sea anemones, which are invertebrate cnidarians, compete for space by actively engaging in combat with members of different clones.1

When individuals from one clone encounter those from another, they recognize non-clonemates through chemically mediated tentacle contact. To defend or secure their territory, the combatants inflate and strike one another using specialized fighting structures called acrorhagi. These marginal tubercles are densely packed with nematocysts—microscopic stinging structures—which are used to slap the opponent. These aggressive encounters can result in the death of one of the anemones, or both may retreat from the area.12