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

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
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
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

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 ....
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern