Class Anthozoa - reef-builders since the Triassic period...

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Class Anthozoa: Sea Anemones and Corals Sea anemones, shown in Figure 12, are solitary polyps 5-100 mm in height and 5-200 mm in diameter or larger. They are often brightly colored and look like flowers (specifically anemones) on the seafloor. You might remember them from the film Finding Nemo . The anemone's thick, heavy body rests on a pedal disk and supports an upward-turned mouth surrounded by hollow tentacles. Sea anemones feed on various invertebrates and fish. They attach to a variety of substrates, or may be mutualistic with hermit crabs, living attached to crab's shell. Corals may be solitary but most today are colonial. The majority of corals occur in warm shallow waters; the accumulation of their calcium-carbonate remains builds reefs. Some corals occur in colder waters, so the mere presence of coral does not necessarily indicate a tropical environment. Modern scleractinian coral, dominant
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Unformatted text preview: reef-builders since the Triassic period (some 230 million years ago), have symbiotic photosynthetic dinoflagellates living within the coral body. These dinoflagellates are in the genus Symbiodinium , and are termed collectively zooxanthellae, shown in Figure 13a. Figure 13b illustrates several living coral tyypes. Cells are organized into tissues. The adult in most species of cnidarian is radially symmetrical. The typical cnidarian life cycle involves both sexual and asexual reproduction. A bilaterally symmetrical larva known as a planula (shown in Figure 11), develops from a zygote . The planula moves around and eventually settles down in an appropriate location and grows into the adult polyp . The polyp grows and may eventually reproduce asexually to form medusae . Each medusa develops gonads and uses meiosis to form gametes ....
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This note was uploaded on 11/29/2011 for the course BIO BSC1010 taught by Professor Gwenhauner during the Fall '10 term at Broward College.

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Class Anthozoa - reef-builders since the Triassic period...

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