These tentacles will extend in an active search for small prey. The anemones will also alter their shape of the column when the isolated sense cells detect the presence of food, whether it is plankton or organic remains. Conceivably, in the still waters of a rock pool free swimming creatures will wander into the tentacles. However, there are two reasons why this unlikely. Firstly, in the still waters there is very little movement.
Low tide is the quiescent period when the tide pool inhabitants seek shelter.
Only when the incoming tide cascades over the pool are the various small fish and prawns stimulated to move. Secondly, the larger animals, prawns and such like have evolved to resist the entrapment of the tentacles. In the hard-shelled condition, prawns would normally be able to break free from the stinging tentacles, and most rock pool fish will quickly dart away at the touch of a tentacle. After a large item of food has been dispatched down its tubular gullet, the Beadlet Anemone may contract for a period of up to one hour. Afterwards, it will expand to its fullest extent whilst it completes its digestion process.