Sea Anemone
Predatory marine invertebrates with stinging tentacles, related to corals and jellyfish.
Sea anemones (ə-NEM-ə-nee) are a group of predatory marine invertebrate animals constituting the order Actiniaria. They are named after the terrestrial flowering plant Anemone due to their colorful appearance. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. As cnidarians, they are related to corals, jellyfish, tube-dwelling anemones, and Hydra. Unlike jellyfish, sea anemones do not have a medusa stage in their life cycle.
- Phylum
- Cnidaria
- Class
- Anthozoa
- Diet
- Carnivorous (Plankton, Small Fish, Crustaceans)
- Locomotion
- Sessile (mostly), with limited gliding or somersaulting ability
- Defense Mechanism
- Nematocysts (stinging cells)
Lore & Background
A typical sea anemone is a single polyp attached to a hard surface by its base, but some species live in soft sediment, and a few float near the surface. The polyp has a columnar trunk topped by an oral disc with a ring of tentacles and a central mouth. The tentacles can be retracted inside the body cavity or expanded to catch prey. They are armed with cnidocytes (stinging cells). Many species gain additional nourishment from a symbiotic relationship with single-celled dinoflagellates, zooxanthellae, or green algae (zoochlorellae) that live within their cells. Some species live in association with clownfish, hermit crabs, small fish, or other animals to their mutual benefit.
In Their Own Story
On 23 March 2020, Living Coasts, along with other visitor attractions nationwide, temporarily closed during the COVID-19 pandemic and consequent lockdown. On 11 June, the House of Commons debated the reopening of zoos amid mounting concerns that many could face permanent closure without visitor revenue. On 15 June, the Government announced zoos could re-open to the public with strict social distancing rules in place, however Living Coasts remained closed. On 16 June, Wild Planet Trust announced the permanent closure of Living Coasts due to its costbase, need to make efficiencies and inability to afford required substantial maintenance. Homes were sought for the zoo's animals. Despite euthanasia fears, on 19 June 2020 it was then announced that homes had been found for all animals.
Reader's Guide
Sea anemones breed by liberating sperm and eggs through the mouth into the sea. Fertilized eggs develop into planula larvae that are planktonic for a while before settling on the seabed and developing directly into juvenile polyps. They also breed asexually by breaking in half or into smaller pieces that regenerate into polyps. Sea anemones are sometimes kept in reef aquariums; the global trade in marine ornamentals for this purpose is expanding and threatens sea anemone populations in some localities, as the trade depends on collection from the wild.
Did You Know?
- Sea anemones are named after the terrestrial flowering plant Anemone because of their colorful appearance.
- Unlike jellyfish, sea anemones do not have a medusa stage in their life cycle.
- Some sea anemones can exceed 1 meter in diameter, such as Urticina columbiana and Stichodactyla mertensii.
- Clownfish are not affected by their host anemone's sting and shelter among its tentacles.
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