Table of Contents
Table of Contents
- Phylum Coelenterata
- Summary
- What’s Next?
In the previous segment of the chapter ‘Diversity in Living Organisms’, we studied about the
phylum Porifera. In this segment, let us get introduced to the phylum Coelenterata.
What is Phylum Coelenterata?
- The term Coelenterata means organisms which have a hollow body structure. The phylum consists of two major subphyla namely Cnidaria and Ctenophora.
- All the coelenterates show a tissue level of organisation. They usually have a body made up of two layers: the outer layer and the inner layer.
- The basic structure of any coelenterate is composed of a hollow tubular structure and tentacles surrounding the single opening.
- To study the morphology of coelenterates, they are classified into two major categories:
Polyp
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- Polyps are non-motile. The tube-like and cylindrical structure is attached to a support while the tentacles are placed on the upper side.
- The tentacles become the only structures to float around and catch hold of prey.
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For example, sea anemone. It is attached to the substratum with this basal region and has tentacles on top.
Polyp
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- Medusa
- These organisms have umbrella-shaped structures and tentacles attached at the base.
- Medusa