Beadlet anemone (Actinia equina).
In and around rock pools on rocky shores around the coast of Britain.
When exposed to the air, sea anemones look like blobs of jelly stuck to the rocks. The commonest type is the beadlet anemone, which is usually red, but other types can green, blue or purple and some are spotted or striped. When the tide covers them with water their tentacles wave around and they look a bit like a dahlia flower.
Some anemones can move slowly but most burrow into mud or sand, or live with their base attached to a rock. However, despite not being able to move around much, they are quite aggressive predators.
When covered with water, they unfold colourful tentacles armed with stinging cells. When a shrimp or a small fish touches a tentacle, the stinging cells suddenly uncoil and shoot poisoned threads into the victim. The tentacles push the prey into the mouth which is in the middle of the ring of tentacles at the top of the blob.
When the tide goes out, the sea anemone may be exposed to sun and wind for several hours. However, anemones are covered with a slimy mucous, which helps to stop them drying out, and they are usually found on the underside of rocks or in damp cracks and crevices.
To help look after anemones and other seashore wildlife, always put rocks back exactly as you found them.