medusa, in zoology, one of two principal body types occurring in members of the invertebrate animal phylum Cnidaria. It is the typical form of the jellyfish. The medusoid body is bell- or umbrella-shaped. Hanging downward from the centre is a stalklike structure, the manubrium, bearing the mouth at its tip.
What phylum has polyp and medusa forms?
Introduction to Phylum Cnidaria
- Cnidocytes: Animals from the phylum Cnidaria have stinging cells called cnidocytes.
- Cnidarian morphology: Cnidarians have two distinct body plans, the medusa (a) and the polyp (b).
What is the difference between a polyp and medusa body form?
Polyp are sessile while medusa are mobile. Polyp present a tubular shape with the mouth facing the water upwards,while medusa present a bell shape with the mouth facing the water downwards. Polyp do not have a manubrium, while medusa of the class Hydrozoa present a tube hanging down from the bell known as manubrium.
What body form do sea jellies exhibit medusa or polyp?
((Figure)). An example of the polyp form is found in the genus Hydra, whereas the most typical form of medusa is found in the group called the “sea jellies” (jellyfish). Polyp forms are sessile as adults, with a single opening (the mouth/anus) to the digestive cavity facing up with tentacles surrounding it.
What do you mean by polyp and medusa?
Polyp is a sessile life cycle stage of species who belong to phylum cnidaria. Famous examples of polyp are sea anemones and adult corals. Medusa is a life cycle stage of the species who belongs to cnidaria phylum. One of the most common examples of species having a medusa life cycle is Hydrozoa or jellyfish.
What are medusa polyps?
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.
What is medusa and polyp?
What differences do you see in the polyp and medusa stages of obelia to that of Aurelia?
A. Medusa:
- It has a small size, often called swimming bell and the medusa is produced by budding from blastostyles of polypoid obelia colony.
- Medusa phase is reduced.
- The bell margin is entire and is provided with few long, solid tentacles.
- The velum contains an endodermal ring canal.
What is a polyp body form?
polyp, in zoology, one of two principal body forms occurring in members of the animal phylum Cnidaria. The lower end of the polyp typically is adapted for attachment to a surface. The body wall consists of an ectodermal, or outer, layer and an endodermal, or inner, layer.
What is the difference between two body forms polyp and medusa exhibited by cnidarians?
Most of the Cnidarian classes utilise polyp and medusa as two stages of their life cycle. Polyps are sessile and asexually reproduce by budding. But, medusa reproduces sexually by producing sperms and eggs. The key difference between polyp and medusa is that polyp is sessile whereas medusa is free-swimming.
What are the differences in a polyp and a medusa?
Difference Between Polyp and Medusa Movement. Polyp: Polyp is a sessile organism. Body Structure. Polyp: Body is a cylindrical structure containing a long stalk. Habitat. Polyp: It is found attached to rocks near water mark. Manubrium. Polyp: Manubrium is directly upward since the body is attached to a surface. Velum. Sense Organs. Gastrovascular Cavity. Gonads. Reproduction. Role.
What animal has a polyp and a medusa?
Cnidarians have two body forms-polyp and medusa-which often occur within the life cycle of a single cnidarian. Members of one class of cnidarians, the Anthozoa, exhibit only the polyp body form; most species of the other three classes (hydrozoans, scyphozoans, and cubozoans) alternate in their life cycles between polypoid and medusoid (free-swimming) body forms.
What is the diffence between polyp and Medusa?
The key difference between polyp and medusa is that polyp is a fixed, cylindrical structure, representing the asexual stage and medusa is a free swimming, umbrella-like structure, representing the sexual stage.
What is the evolution of a polyp into a medusa?
Evolution of polyp and medusa Polyp are the primitive form of Cnidaria , with medusa being the more evolved form. Medusa are free swimming, reproduce sexually with cross-fertilization increasing genetic diversity, and present a more complex morphology than the polyp form.
