- Published: 03 February 2010
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Josephine Siedlecka, age 7, of Victoria, B. C., for her qucstion;
Are sea anemones animals or plants?
The experts have sorted all the plants and animals into groups. The sea anemones are classed as Anthrozoa, a lovely word which means flower‑animals. This is fair enough, for sea anemones look like pretty flowers but they are really pretty animals. They enjoy life in shallow water where salty tides spill over rocky pools. We find them in warm waters and cool waters. But the most gaudy ones are found in tropical waters. There they often share the pools along the shore with their cousins, the; corals,
When the tide is out, the pools along the beach may be empty, Then the sea anemones look like blobs of pale colored jelly. The tide turns and inches back into the rocky pool. Then the blobs of jelly seem to blossom into a garden of wild flowers. Each one stands on a chubby stem, The head is circled with rows of delicately tinted daisy petals, The word anemone means the wind flower. Perhaps the sea anemone got its name because it seems to wave like a flower in the wind,
However, its petals are really tentacles, little fingers reaching out to find food in the water. Each one is fitted with countless stinging hairs. For the sea anemone is a meat eater. It squats there waiting for its prey to swim by. The pretty thing looks harmless enough to a little fish. But if the fish happens to brush the tentacles, they will sting him and paralyse him.
Now the sea anemone has the job of eating little fish. The flower‑animal has a very simple body. He belongs to a large group of animals called hollow‑insiders. His chubby stalk is quite hollow inside and his hollow serves as a stomach. It also takes oxygen from the water and does the breathing for the little animal.
The bottom of the stalk is a strong foot which can remain firmly fixed on a rock or go for a slow walk. The head end is a round open mouth fringed with tentacles. The outer tentacles are the longest and they serve as the hungry petals that search for food. There are also two smaller .fringes of tentacles. One set fans a constant stream of water into the hollow inside of the sea anemone. It carries in food and oxygen. Another set fans out a stream of water to carry away waste carbon dioxide and bits of useless food. Water is always circulating through the hollow stomach.
The petal tentacles start the poor fish on its way inside the sea anemone. They hold it in the right direction. Other tentacles are busy fanning in a stream of water. This pulls the fish and he gets carried down to be digested. The sea anemone is quite happy to catch one meal while the tide fills his pool. The tide may go out and leave him high and dry. But so long as his soft body stays moist, he can wait for the next tide. If times arc very bad in his pool, it does not bother him. He can inch his way slowly over the rocky beach until he finds another pool. This time he will choose one nearer the ocean. Then he can be sure that the tide will cover him twice every day, bringing his oxygen and plenty of tasty little fish and maybe a few shrimp. He may even decide to live underwater all the time.