Beadlet anemone
Encyclopedia
The beadlet anemone, Actinia equina, is a common sea anemone
found on rocky shores around all coasts of the United Kingdom. Its range extends to the rest of Western Europe and the Mediterranean, and probably as far as the coast of West Africa.
Actinia equina can be found both in exposed and sheltered situations. It is highly adapted to the intertidal zone
as it can tolerate both high temperatures and desiccation. The anemone may also be found in regions of variable salinity
such as estuaries
.
Underwater, it displays up to 192 tentacle
s, arranged in six circles. Out of water, the tentacles retract and the anemone resembles a blob of red, brown, green or orange jelly, up to about 5 centimetres (2 in) across. It has bright blue spots (known as acrorhagi) located just beneath the tentacles, organised as an external ring containing stinging cells located at the top of the column that it uses to fight over territory. The acrorhagi contains the cnidocysts which themselves contain the nematocysts. There is some evidence that the various colour forms may in fact be different species.
Actinia equina is similar in form to the strawberry anemone
(Actinia fragacea) but is a uniform colour and is typically rather smaller.
Sea anemone
Sea anemones are a group of water-dwelling, predatory animals of the order Actiniaria; they are named after the anemone, a terrestrial flower. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Zoantharia. Anthozoa often have large polyps that allow for digestion of larger...
found on rocky shores around all coasts of the United Kingdom. Its range extends to the rest of Western Europe and the Mediterranean, and probably as far as the coast of West Africa.
Actinia equina can be found both in exposed and sheltered situations. It is highly adapted to the intertidal zone
Intertidal zone
The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...
as it can tolerate both high temperatures and desiccation. The anemone may also be found in regions of variable salinity
Salinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
such as estuaries
Estuary
An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....
.
Underwater, it displays up to 192 tentacle
Tentacle
A tentacle or bothrium is one of usually two or more elongated flexible organs present in animals, especially invertebrates. The term may also refer to the hairs of the leaves of some insectivorous plants. Usually, tentacles are used for feeding, feeling and grasping. Anatomically, they work like...
s, arranged in six circles. Out of water, the tentacles retract and the anemone resembles a blob of red, brown, green or orange jelly, up to about 5 centimetres (2 in) across. It has bright blue spots (known as acrorhagi) located just beneath the tentacles, organised as an external ring containing stinging cells located at the top of the column that it uses to fight over territory. The acrorhagi contains the cnidocysts which themselves contain the nematocysts. There is some evidence that the various colour forms may in fact be different species.
Actinia equina is similar in form to the strawberry anemone
Strawberry anemone
The Strawberry anemone is an Anthozoan that appears to be confined to the English Channel and south-west England where it is generally found on rocks of the lower shoreline. It has a column which is typically red or dark red, with spots of green, yellow or blue. The tentacles are usually red or...
(Actinia fragacea) but is a uniform colour and is typically rather smaller.