Question

What is medusa?

Answer 1

Hint: Medusa is one of two main body shapes seen in members of the invertebrate animal phylum Cnidaria, according to zoology. It is the jellyfish's most common form. The medusa is a free-swimming organism that propels itself across the water via repetitive muscle contractions of the bell.

Complete answer:
A medusa (plural: medusae) is a type of cnidarian with a body structured like an umbrella in biology. The polyp is the other major body shape.
Medusae come in a variety of shapes, from bell-shaped to thin disk-shaped, barely convex above and only slightly concave below. The mouth is on the lower surface, which may be partially closed by a membrane extending inward from the margin; the upper or aboral surface is called the exumbrella, and the lower surface is called the subumbrella; the upper or aboral surface is called the exumbrella, and the lower surface is called the subumbrella; the mouth is on the lower surface, which may be partially closed by a membrane extending inward from the margin (called the velum).

The gastrovascular cavity and radiating canals that extend toward the periphery make up the digestive cavity; these canals can be simple or branched, and their number can range from a few to many. Sensory organs and tentacles are found along the disk's edge.

Medusae are the sexual individuals of many species in the Hydrozoa class, and they alternate in the life cycle with asexual polyps. Hydrozoans in the medusa form are known as hydromedusae.
A polyp is a cnidarian that attaches to a surface, while a medusa is a free-floating cnidarian. A species of cnidarian can take either form at any time during its life.
Scyphozoa (the common, colourful, huge jellyfish) and Cubozoa are the most prevalent medusa species. These are the only classes in which medusae can be found, with the exception of freshwater hydrozoans likeCraspedacusta sowerbii.
Medusae can have a lot of tentacles to catch their prey with. A medusa may touch people who are swimming in the ocean. Their tentacles are long and slender, with deadly stinging cells covering them (known as nematocysts). They inject a toxin that renders small fish immobile. Those that have been stung should seek medical help. Some people have died as a result of severe medusa stings.

Note:
In zoology, a polyp is one of two main body shapes found in members of the Cnidaria animal kingdom. The polyp is sessile and can be solitary, as in a sea anemone, or colonial, as in coral (attached to a surface). Coral polyps, like sea anemones and jellyfish, are small, soft-bodied animals. A calicle, a hard, protective limestone skeleton, is found at their base.