EVERYDAY SCIENCE

Detailed explanation-1: -Polyps are the sessile or fixed individuals, while medusae are motile or free-swimming zooids . Polyps appear more or less cylindrical, whereas medusae appear umbrella-shaped. Cnidarians can exist as polyps or medusae as adults and planulae as larvae.

Detailed explanation-2: -1. Movement of Polyp and Medusa: Polyp is a sessile life stage of the cnidaria phylum whereas medusa is totally opposite i.e they have a mobile life cycle stage of the cnidaria phylum.

Detailed explanation-3: -Medusa bodies are shaped like an umbrella with the mouth and tentacles hanging down in the water. The mouth leads upward into the gastrovascular cavity. Medusae (plural; the singular form is medusa) are not sessile, but rather are motile, meaning that they swim freely in the ocean (Fig. 3.25 C).

Detailed explanation-4: -There are two basic cnidarian body shapes: a polyp form, which is attached to a surface; and an upside-down free-floating form called a medusa. Some cnidarians change form at different phases of their life cycle, while others remain in one form for their entire life.

Detailed explanation-5: -Medusa is a free-swimming, umbrella-like structure representing the sexual stage. The polyp is a sessile life cycle stage of the Cnidaria phylum, whereas Medusa is a mobile life cycle stage of the Cnidaria phylum.