Morphological patterns of cnidarians

Question

Write down the two major morphological patterns of cnidarians? Concerning locomotion how do these forms discriminate from each other?

Answer 1

Morphologically, cnidarians categorize as medusae or polyps. Polyps are cylindrical and medusae are circular convex, like umbrella. Both shapes encompass tentacles.

In general polyps are sessile however some species, like hydra, can move through alternating contact points on substrate and performing somersaults. Medusae can move expelling water jets by the contraction of body. Some cnidarians exchange medusoid and polypoid forms in their life series.