Medusa, on the other hand, is the second body form obtained by the Cnidarians. The umbrella-like and drooping structure of a medusoid is its key appearance indicator. The manubrium, a vine feature with the mouth at its apex, hangs downwards from the middle. A polyp is a motile lifespan phase within the Cnidarian phylum of creatures. Polyps are seen in adult reefs and sea urchins.
The opening and tendrils are pointing in the direction of the ocean water flow to trap the planktons for food. Polyps can reproduce either asexually by budding and sexually corals are gender-based organisms. Different sexes occur in corals, with maybe some corals becoming males and others females. Some species of corals are hermaphrodites and the gender depends upon the temperature of the water they reside in. Budding happens when a spherical area of tissue is evaginated during asexual reproduction.
Speaking about their body structure, Polyps are cylindrical in form and have a fixated shaft-like base. Individuals in a swarm of invertebrate sea organisms belonging to the group Bryozoa are occasionally referred to as polyps, although they are typically referred to as zooids the name for these phyla polyp is derived from zooids themselves. Hydrozoa taxa can take the form of medusas or jellies. It has an elongated axis. Polyps can either be solitary or in groups.
The hold fast called paddle disc holds the polyp in a position. Mesoglea is preset between the single layered ectoderm and endoderm but it is not that much thick. It is considered to be living fossils as even after the mass extinction event it is still surviving since more than half a billion years.
They are dependent on others and reproduce through asexual budding. The umbrella like motile medusa is free to move. It represents the sexual phase. It is retrograde form of polyp. Medusa is flattened sac-like floating with its mouth facing down and tentacles above. The upper body of medusa is called exumbrella while the lower part is called subumbrella. In Portuguese man-of-war the upper part called exumbrella are slightly convex and sometimes round or egg-shaped while subumbrella is concave.
There are three type of tentacles. Every set of tentacle play different role, like one set is responsible for reproduction, the other is responsible for protection while one set is for feeding. Adult corals and sea anemones are examples of polyps. What is Medusa? Medusa is a mobile life cycle stage of the species belonging to the Cnidaria phylum. Species of the Hydrozoa class exist in medusa form or jellyfish.
Difference between polyp and medusa Movement of polyp and medusa Polyp is a sessile life cycle stage of the Cnidaria phylum, while medusa is a mobile life cycle stage of the Cnidaria phylum. Morphology of polyp and medusa Polyps have a tubular shape and are fixed at their base. Reproduction of polyp and medusa Polyp reproduction can be asexual by budding through the evagination of a circular are of tissue including the endoderm and ectoderm, or sexual by spawning following the release of pheromones.
Medusa, however, can only reproduce sexually, giving birth to medusa only. Evolution of polyp and medusa Polyp are the primitive form of Cnidaria, with medusa being the more evolved form. Medusa is a mobile life cycle stage of the Cnidaria phylum, contracting with it muscular bell. Polyp have a tubular shape and are fixed at their base, with the mouth present at the other end of the tube facing the water. Medusa have a bell shape, with tentacles hanging down. Polyp do not have a manubrium.
Medusa of the Hydrozoa class present a tube hanging down from the bell known as manubrium. Polyp do not possess any sense organs. Medusa possess photoreceptors and gravity-sensing statocytes surrounding the bell. Polyp can reproduce asexually by budding, or sexually by spawning following the release of pheromones.
Medusa reproduce exclusively sexually. Polyp produce either polyp or medusa by budding. Medusa can produce only medusa. Polyp are primitive, being sessile, lacking sense organs, and reproducing mostly asexually. Medusa are more evolved, being mobile, presenting sense organs such as the photoreceptors and the statocytes, and reproducing sexually which promotes genetic diversity. Summary of polyp and medusa Polyp and medusa are two life cycle stages of the Cnidaria phylum, alternating in some species, while other Cnidaria species exist as either polyp in the case of the Anthozoa class or medusa in the case of the Hydrozoa class.
Polyp and medusa present some major differences: 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. Polyp do not possess sense organs, while medusa possess photoreceptors and gravity-sensing stratocytes surrounding the bell.
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