The beadlet anemone (Actinia equina) is small red anemone that looks like red circular blobs on rockpools and is found on most UK rocky shores. They only reveal their short tentacles when underwater and use the base of their body as a strong sucker to keep them attached to the shore. They hide their tentacles when exposed as a way to tolerate high temperatures and lack of water. These anemones can be 5cm in diameter and have up to 192 tentacles! They are usually dark red in colour but can also have some browns, greens and oranges and if you look closely you might be able to see blue beads just under their tentacles, these are called acrorhagi and contain stinging cells. Don’t worry though they aren’t dangerous to humans and are used to deter neighbouring individuals.
Kingdom: Animalia (Animals)
Phylum: Cnidaria (Aquatic animals that have special cells used to catch prey)
Class: Anthozoa (Marine invertebrates like anemones and stony and soft corals)
Order: Actiniaria (Sea anemones)
Family: Actiniidae (The largest sea anemone family)
Genus: Actinia (Anemones that display hetermorphosis – developing a second mouth if cut!)
Species: A. equina
You can find these anemones all year round on rocky shores all over the British Isles, as well as all along Western Europe and the Mediterranean Sea, and even as far as the Atlantic coast of Africa and South Africa. Because they use their body as a sucker, these little anemones need a hard surface to attach to. When rockpooling, you can find them on exposed and sheltered shores from the upper to lower shore as well. They have a depth range of up to 20m.
Beadlet anemones use stinging cells, or nematocysts, which act like mini harpoons, to inject their prey with venom. They are one of the most aggressive anemones and will eat just about anything they can catch such as shrimp, crabs, mussels and small fish.