Anthozoa is a class of marine invertebrates which includes the sea anemones, stony corals and soft corals. Adult anthozoans are almost all attached to the seabed, while their larvae can disperse as part of the plankton. The basic unit of the adult is the polyp; this consists of a cylindrical column topped by a disc with a central mouth surrounded by tentacles. Sea anemones are mostly solitary, but the majority of corals are colonial, being formed by the budding of new polyps from an original, founding individual. Colonies are strengthened by calcium carbonate and other materials and take various massive, plate-like, bushy or leafy forms.
The aggregating anemone, or clonal anemone, is the most abundant species of sea anemone found on rocky, tide swept shores along the Pacific coast of North America. This cnidarian hosts endosymbiotic algae called zooxanthellae that contribute substantially to primary productivity in the intertidal zone. The aggregating anemone has become a model organism for the study of temperate cnidarian-algal symbioses. They are most well known for the ability to clone themselves.
Actinia fragacea, commonly known as the strawberry anemone, is a species of sea anemone of the order Actiniaria, that occurs from Norway to Africa, including adjacent islands and the Mediterranean. It is generally found on rocks of the lower shoreline and depths up to 8–10 metres (26–33 ft).
Corynactis californica is a brightly colored colonial anthozoan corallimorph. Unlike the Atlantic true sea anemone, Actinia fragacea, that bears the same common name, strawberry anemone, this species is a member of the order Corallimorpharia, and is the only member found in the North American West Coast. Other common names include club-tipped anemone and strawberry corallimorpharian. The anemone can live up to at least 50 meters (160 ft) deep on vertical rock walls, and at the bottom of kelp forests. It is known to carpet the bottom of some areas, like Campbell River in British Columbia, and Monterey Bay in California.
The starburst anemone or sunburst anemone is a species of sea anemone in the family Actiniidae. The sunburst anemone was formerly considered the solitary form of the common aggregating anemone, but was identified as a separate species in 2000.
Sea anemones are a group of predatory marine invertebrates constituting the order Actiniaria. Because of their colourful appearance, they are named after the Anemone, a terrestrial flowering plant. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. As cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and Hydra. Unlike jellyfish, sea anemones do not have a medusa stage in their life cycle.
Anthopleura xanthogrammica, or the giant green anemone, is a species of intertidal sea anemone of the family Actiniidae.
Actinia tenebrosa, commonly known as the waratah anemone, is the most common species of sea anemone found in the waters of eastern Australia and New Zealand. It is found relatively high on the seashore, in rock pools, and various cracks and shaded surfaces such as under rock overhangs in the intertidal zone.
Calliactis parasitica is a species of sea anemone associated with hermit crabs. It lives in the eastern Atlantic Ocean and Mediterranean Sea at depths between the intertidal zone and 60 m (200 ft). It is up to 10 cm × 8 cm in size, with up to 700 tentacles, and is very variable in colour. The relationship between C. parasitica and the hermit crab is mutualistic: the sea anemone protects the hermit crab with its stings, and benefits from the food thrown up by the hermit crab's movements.
Protanthea simplex is a species of sea anemone found in deep water off the coasts of north west Europe. It is the only species in the monotypic genus Protanthea.
Metridium farcimen is a species of sea anemone in the family Metridiidae. It is commonly known as the giant plumose anemone or white-plumed anemone. It is found in the eastern Pacific Ocean from Alaska down to Catalina Island, California.
Actinia bermudensis, the red, maroon or stinging anemone, is a species of sea anemone in the family Actiniidae.
Cerianthus lloydii is a species of tube-dwelling sea anemone in the family Cerianthidae. It is sometimes called the lesser cylinder anemone and is found in shallow seas around the coasts of north west Europe.
Actinia cari is a species of sea anemone in the family Actiniidae. It is native to the Mediterranean Sea where it is an uncommon species.
Phyllodiscus is a monotypic genus of sea anemones in the family Aliciidae. The only species is Phyllodiscus semoni, commonly known as the night anemone, which is native to shallow seas in the central Indo-West Pacific, such as Indonesia, the Philippines and southern Japan. It is venomous and can cause a painful, long-lasting sting to humans. It is called unbachi-isoginchaku in Japanese which translates as "wasp-sea anemone".
Actinia mediterranea is a common sea anemone found on rocky shores all along its range in the Mediterranean Sea, Portuguese shores and the coast of north western Africa. Because of its strong resemblance with Actinia equina, they are often confused and share certain common names as Beadlet anemone.
Anthopleura thallia, commonly known as the glaucous pimplet, is a species of sea anemone in the family Actiniidae. It is found in shallow water in the northeastern Atlantic Ocean and the Mediterranean Sea.
Diadumene cincta is a small and delicate, usually orange, sea anemone. It has a smooth slender column and up to 200 long tentacles, and normally grows to a length of up to 35 mm (1.4 in), with a base of 10 mm (0.4 in), but specimens twice this size have been recorded. Diadumene cincta is found in the northeastern Atlantic Ocean.
Actinia striata is a species of sea anemone endemic to the Mediterranean Sea.
Granny was the affectionate name eventually given to a beadlet sea anemone, Actinia equina, which in 1828 was taken from a rocky shore at North Berwick in Scotland by an amateur naturalist, John Dalyell. During her long life through the Victorian era, she was cared for by a series of Edinburgh naturalists. Long outliving Dalyell, this sea anemone lived alone in a jar where she gave birth to several hundred offspring before her death in 1887.
