What is the difference between a medusae and a polyp?
Polyps have a tubular shape and are fastened at their base, with the mouth facing the water at the other end of the tube. Medusa has a bell-shaped body with hanging tentacles. Polyp does not have a manubrium. The Hydrozoa class’s Medusa has a manubrium, a tube that hangs from the bell.
How does a polyp turn into a medusa?
In organisms that exhibit both forms, such as members of the cosmopolitan genus Obelia, the polyp is the asexual stage and the medusa the sexual stage. In such organisms the polyp, by budding, gives rise to medusae, which either detach themselves and swim away or remain permanently attached to the polyp.
What is the medusa stage?
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. Morphologically, a medusa is formed by a bell capable of muscular contractions which enables the medusa to swim.
Which group alternates between polyps and medusae?
Cnidarians
Cnidarians can reproduce sexually or asexually. When it comes to reproduction, the oldest animal phyla have the most flexibility. Many cnidarians alternate between polyp and medusa forms during their life.
What do we call the immature medusae?
The process by which new medusae are produced is called ‘strobilation’ and involves metamorphosis of the end of a scyphistoma into an ‘ephyra’, an immature medusa, that subsequently detaches and swims away.
What are characteristics of medusae?
The medusa is a free-swimming form; it moves by rhythmic muscular contractions of the bell, providing a slow propulsive action against the water. The other principal body type of the adult cnidarian is the polyp, a stalked, sessile (attached) form.
What is a jellyfish polyp?
Jellyfish have a stalked (polyp) phase, when they are attached to coastal reefs, and a jellyfish (medusa) phase, when they float among the plankton. The medusa is the reproductive stage; their eggs are fertilised internally and develop into free-swimming planula larvae.
How do medusae reproduce?
In the adult, or medusa, stage of a jellyfish, they can reproduce sexually by releasing sperm and eggs into the water, forming a planula. It is this form that grows into the adult medusa jellyfish. The jellyfish sting actually comes from tiny nematocysts, or stinging cells, on the jellyfish body.
Are sexes separate in coelenterates?
Looking into their sexuality most of the organisms belonging to this phyla appear to be gonochorists/ unisexual with exceptions of few hermaphrodites. They are capable of undergoing both sexual and asexual reproduction along with other means like budding and regeneration.
Whats a jellyfish polyp?
What is the difference between a polyp and a medusa?
Difference Between Polyp and Medusa Difference Between Medusa and Polyp Difference Between Medusa and Polyp Polyp Medusa Mobility Mobility Polyps are sessile Medusae are mobile Shape Shape
What is a colon polyp?
A colon polyp is a small clump of cells that forms on the lining of the colon. Most colon polyps are harmless. But over time, some colon polyps can develop into colon cancer, which may be fatal when found in its later stages. Anyone can develop colon polyps.
What is a Medusa in biology?
In biology, a medusa (plural: medusae) is a form of cnidarian in which the body is shaped like an umbrella. The other main body-form is the polyp.
What is polyp in Cnidaria?
polyp and medusa, names for the two body forms, one nonmotile and one typically free swimming, found in the aquatic invertebrate phylum Cnidaria (the coelenterates). The polyp is a sessile, or nonmotile, organism; well-known solitary polyps are the sea anemone and the freshwater hydra.