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The Sea Anemones
by Evan McNamara
Phylum:
Cnidaria
Class: Anthozoa
Order: Actiniaria
Family: Aiptasiidae
Basic Information
The Sea Anemone, is also called, "the flowers of the sea" and the Pale Anemone. The Sea Anemone is an invertebrate, "possessing no backbone" (95% of the earth's animals are invertebrates). Being part of the Cnidaria phylum they are family with corals, jellyfish, and hydras. Sea Anemones are found in Bermuda and around coastal North Carolina, and are also found throughout the Gulf of Mexico and in the Caribbean. They have stinging cells in their tentacles, which allow Cnidarians to capture prey and also defend themselves from predators. They have a single body part that serves as the stomach, lung, intestine, and basically all other organs. They also have a mouth, which also acts as its anus. Surrounding the mouth the Sea Anemone as many tentacles which contain nematocysts at the ends. The Sea Anemones attach themselves to rocks, the ocean floor, or even mangrove roots, usually in shallow parts of the ocean just below the low-tide line. And once settled do not move unless they are unhappy with that location.
The Sea Anemones have a symbiotic relationship with algae named zooxanthellae. The Sea Anemone and the zooxanthellae work together. The algae are found within the gastrodermal cells of the Anemone. The Sea Anemone uses the photosynthetic products from the zooxanthellae as their carbohydrates, and the zooxanthellae use the nutrients of the Anemone that come out of the Anemone as waste. These two organisms function as one using the other to benefit themselves.
 Curlique Anemone |
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Long Tentacled Anemone
The Cnidaria Phylum
A Greek word "cnidos" means "stinging nettle", which created this phylum's name. The defining characteristic of this phylum is their nematocysts or the stinging tentacles. When attacked or hungry the Cnidarians inject their tentacle into the prey or predator. Often they inject a barbed thread and often some kind of poison. Their "bag-shaped" body with only one mouth, no anus, is surrounded by tentacles with nematocysts. The layers of the organisms include two layers of cells; ectoderm (an outer layer) and one inner layer called the endoderm. There is also a jelly like substance, between the two main inner and outer layers, called mesogloea. Jellyfish, another organism in the Cnidaria Phylum, differs from the Sea Anemones because the Jellyfish are free floating (called medusae), while the Sea Anemones are attached to a rock or the ocean floor (called polyps).
 Saddle Anemone |
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Our Care with Sea Anemone
In our Marine Biology class we studied the Sea Anemones for a couple weeks watching them grow. Each group of students took care of a number of Sea Anemones during this time. The Sea Anemones where kept in a small glass container about two inches deep, with a few small pebbles that they could attach themselves to. The student groups recorded the day and time of feeding, along with days when the water was changed. Some Anemones lived the full time of the testing while other died after a few days. The anemones that lived longer grew to about an inch in height and about half an inch wide. After the growing had ended we dissected the anemones and examined the Aiptasia pallida. We also examined the tentacles and the nematocysts inside of the tentacles.
Bibliography
1.
Sea Anemones: Live "Flowers" For Your Saltwater Tank
www.pettalk.com/seaanemones.html
2.
Introduction to the CnidariaÉJellyfish, corals, and other stingersÉ
www.ucmp.berkeley.edu/cnidaria/cnidaria.html
3.
Encarta- Sea Anemone
http://encarta.msn.com