Anemones are very simple animals. Their bodies are simple sacks (the column), with a mouth surrounded by tentacles at one end and a sticky base at the other. The stinging tentacles capture prey and drag the food towards the mouth. The mouth is used both to take in food and to expel waste. The sticky base holds them securely to the rocks. Despite their simplicity, some species of anemone are extremely successful at coping with conditions on the shore. They may withstand long periods out of water and large fluctuations in temperature.

Anemones are not plants but predatory animals, can move if condistions become unfavourable, but are normally static. If any small fish, prawns or smaller organisms passes closly and lightly brushes the tenticles, they are triggered and fire a coiled filaments into the prey, poison is injected and the prey paralised. The prey is then passed by the tenticles to the anemones mouth, which is in the centre of the column. Its swallowed, digested and the waste products are expelled.

Remember what these creatures do to fish and some people are allergic to them, so touch with care!

  Beadlet Anemone Actinia equina (Linnaeus)

The most common anemone on Britain’s rocky shores, the beadlet anemone may be found in rock pools with their tentacles out ready to sting prey, or it may be found out of the water in crevices looking like blobs of jelly.

The beadlet anemone is able to catch shrimps or small fish that may pass unsuspectingly over its tentacles. The prey is taken whole into the hollow sac-like body through the mouth. The stinging tentacles are also used in defence. If two beadlets touch tentacles, one will attack the other with its stinging tentacles until the defeated beadlet moves away. Red beadlets are more aggressive than green ones and almost always win these fights.

In Cornwall, the beadlet anemone has been referred to as the ‘blood sucker’ due to the way it sucks small prey dry before disgorging them. The eggs of this anemone are kept within the adult until they develop into miniature versions of the parent.

• Habitat

  • Occurs in rockpools and in rock crevices from the middle shore down to the lower shore.

• Key Identification Features

  • Normally red but can be brown, orange or green. Often has a blue line around the edge of its base.

  • Ring of blue warts at the base of each tentacle.

  • Up to 5 cm in diameter.

Strawberry anemone Actinia fragacea (Tugwell)

A species only found in the south-west of Britain, the strawberry anemone is very similar in appearance to the beadlet anemone (Actinia equina). At one time the two were thought to be the same species, but they are now considered to have significant genetic and ecological differences. They also exhibit consistently distinct differences in size and colouration. The strawberry anemone reaches a larger size than the beadlet.

The strawberry anemone appears to be less tolerant of exposure than the beadlet anemone and is found only on the lower shore.

• Habitat

  • Found on rocks and stones on the lower shore.

• Key Identification Features

  • Red to reddish brown with many green spots.

  • Up to 8 cm in length.

Snakelocks anemone Anemonia sulcata (Forskal)

This anemone is a southern species. It is common on the south-west coast of Britain but its numbers appear to be affected by severe winters. Large numbers of this anemone are found attached to hard substrates in St Ives Bay and the Hayle Estuary.

Unlike the beadlet anemone (Actinia equina) the snakelocks is unable to withdraw its tentacles into its body. It is, therefore, less able to cope with living out of the water and is usually found in rock pools.

The snakelocks anemone often has algae living within the tissues of its body. The algae are believed to gain protection and obtain nutrients and carbon dioxide from the anemone. The anemone is likely to benefit from the production of organic compounds by the algae. The algae may also help to remove waste products produced by the anemone.

The anemone has been observed to reproduce by splitting into two.

The sting of large specimens of this anemone can be painful to humans.

• Habitat

  • Found in rock pools on the lower shore and on eel-grass (Zostera marina) strands.

• Key Identification Features

  • Grey or green tentacles tipped with purple.

  • The sticky tentacles do not fully retract.

  • Up to 18 cm across in length.

Daisy anemone Cerus pedunculatus (Pennant)

The daisy anemone is a southern species, and is common along the western and southern coasts of Britain. It may be found in large numbers carpeting muddy gravel areas of rock pools or on soft stable sediment such as that found amongst sea grass beds. If the anemone is of the type where the tentacles are banded it creates a speckled effect and this serves as good camouflage in the gravel. The column of the anemone is often hidden in the mud and they may sometimes sink their bodies completely under the sediment.

The eggs of this anemone are kept within the adult until they develop into miniature versions of the parent.

• Habitat

  • In rock pools and in soft sediment areas from the middle shore down to 25 m.

• Key Identification Features

  • Grey or orange with light brown tentacles which may be banded.

  • A large number of very short tentacles spread out around a tentacle-free central region.

  • Base up to 4 cm in diameter.

  • The column of the anemone is often hidden under the sediment.

Jewel anemone Corynactis viridis (Allman)

These striking anemones are aptly named. They exhibit a wide variety of bright colours and are often found clustered together in large numbers. Like other anemones, the jewel anemone can reproduce both sexually and by simply splitting into two. In the case of the former, sperm from one anemone is washed into the mouth of another anemone, and the eggs are fertilised in the latter anemone’s body cavity. Jewel anemones frequently just divide into two. For this reason, distinct coloured patches of anemones occur, with each patch having derived from a single anemone.

A southern species, the jewel anemone is a common sight in deep water off the south-west coast. Patches of anemones may also be found on lower rocky shores. Large numbers are found on rocky areas of St Ives Bay and the Hayle Estuary.

• Habitat

  • Lower rocky shores, beneath overhangs away from the light.

• Key Identification Features

  • Tentacles end in a small knob.

  • Bright red, green, orange, pink, grey or white in colour with translucent tentacles.

  • Base only 1 cm in diameter.

Trumpet anemone Aiptasia mutabilis (Gravenhorst)

The trumpet anemone is a rare species in Britain that is only found in the south-west. Populations of the trumpet anemone have been recorded on the rocky shores of Looe island. This species cannot retract its tentacles but can pull itself down onto the rocks using its tall, thin column. It is reported to reproduce sexually and by simply dividing into two.

• Habitat

  • Found on the lower shore and down to 30 m. Often amongst the holdfasts of the kelp Saccorhiza but also in pools and under rocks.

• Key Identification Features

  • Tall, trumpet shaped column.

  • Brown or khaki colour with white or pale blue lines on central region.

  • Long thin tentacles surround a tentacle-free central region.

  • Diameter across tentacles up to 15 cm.