In this article we will discuss about the structure of Aurelia with the help of a diagram.
1. It is a cosmopolitan jelly fish which is found in coastal waters.
2. The adults are exclusively medusoia forms.
3. The polyp is represented by schyphistoma and hydra tuba stages.
4. The body is like an inverted bowl or umbrella and is radially symmetrical. The margins of umbrella bear tentacles and is notched at 8 points.
5. Each notch has a pair of soft & leaf – like marginal lappet and one tentaculocyst in between the lappets.
6. The outer convex surface of bowl is known as umbrella surface and the lower concave surface as subumbrellar surface.
7. The lower concave subumbrellar surface bears a small manubrium (mouth) and gives off four long oral arms along the radiae.
8. Velum is absent but endodermal gastric tentacles are present.
9. In each inter-radial space is present a globular structure the gastric pouch.
10. From each gastric pouch comes out many branched and un-branched radial canals which run along subumbrellar surface and open into a circular canal which runs along the margin.
11. Along the roof, in between the arrows, lie reddish and horse-shoe-shaped gonads.
12. Sexes are separate and they exhibit alternation of generation.