In this article we will discuss about the structure of sea-anemone (adamsia) with the help of a diagram.
1. It is commonly called sea-anemone and is a marine commensal which is frequently seen attached to empty gastropod shells in which hermit crabs (Eupagurus prideauxi) live.
2. In this example of commensalism both sea-anemone and hermit crab exhibit physiological treaty. The anemone is carried to distant places by hermit crab and thus is helped in distribution and food finding and the hermit arab is protected from enemies because the anemone is unpalatable and possesses nematoblasts or stinging cells.
3. The adults are exclusively polypoid, solitary and are radially symmetrical.
4. The body is cylindrical and is distinguished into a flat pedal disc, a column and an oral disc.
5. The oral disc is beset with a ring of hollow and un-branched tentacles and bears a large central mouth situated on a raised area.
6. At the joint of column and pedal disc, there are present a few rounded cinclidal tubercles.
7. Pedal disc is flat, sucker-like and bilobed and thus helps in attachment.
8. Skeleton is absent, tentacles and mesentaries are in multiples of six.
9. Siphonoglyphs two in the pharynx.
10. Gonads are located on mesentaries.
11. Sexes are separate and they reproduce sexually and asexually.