What is polyp in cnidarians?

Asked By: Rambha Lillis | Last Updated: 6th March, 2020
Category: medical health digestive disorders
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Polyp, in zoology, one of two principal body forms occurring in members of the animal phylum Cnidaria. The polyp may be solitary, as in the sea anemone, or colonial, as in coral, and is sessile (attached to a surface). The lower end of the polyp typically is adapted for attachment to a surface.

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Keeping this in consideration, what is polyp in Coelenterata?

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.

Also Know, what is the polyp and medusa forms of cnidarians? Two distinct body plans are found in Cnidarians: the polyp or tuliplike “stalk” form and the medusa or “bell” form. ((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).

Simply so, what is the function of a polyp?

Polyps extend their tentacles, particularly at night, containing coiled stinging nettle-like cells or nematocysts which pierce and poison and firmly hold living prey paralysing or killing them.

What is a Medusa in cnidarians?

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. Medusae vary from bell-shaped to the shape of a thin disk, scarcely convex above and only slightly concave below.

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What is a polyp Hydra?

Hydra are small polyps from 1 to 20 mm in body length. The body is crowned by up to 10 or 12 tentacles. Usually the tentacles are approximately the same length as the body but may be somewhat shorter, particularly in the green hydra, and can exceed 20 cm in length in hungry brown hydra in quiet water.

What is a polyp in biology?

Polyp. Definition. noun, plural: polyps. (1) (zoology) The hollow, columnar, sessile form of Cnidarians (as opposed to the medusa form) (2) (pathology) An abnormal (usually benign) pedunculated growth, protruding from a mucous membrane.

Where do polyps live?

Coral organisms, called polyps, can live on their own, but are primarily associated with the spectacularly diverse limestone communities, or reefs, they construct. Coral polyps are tiny, soft-bodied organisms related to sea anemones and jellyfish.

Is Hydra a polyp or medusa?

Hydra exists in both forms: Polyp and Medusa. These forms are dependent upon nutritional content of the living environment. Medusa is the adult and sexual form whereas Polyp is juvenile and asexual form. Under harsh living conditions and starvation, hydra reproduces sexually.

How does polyp form?


Healthy cells grow and divide in an orderly way. Mutations in certain genes can cause cells to continue dividing even when new cells aren't needed. In the colon and rectum, this unregulated growth can cause polyps to form. Polyps can develop anywhere in your large intestine.

What are cancerous polyps?

Colorectal cancer usually begins as a "polyp," a nonspecific term to describe a growth on the inner surface of the colon. Polyps are often non-cancerous growths, but some can develop into cancer. The two most common types of polyps found in the colon and rectum include: Hyperplastic and inflammatory polyps.

Is a jellyfish a polyp?

Corals, sea anemones and jellyfish belong to a group of animals called cnidarians. They have a simple body consisting of a central gut cavity surrounded by tentacles. 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.

Why is sea anemone a polyp?

They are named after the anemone, a terrestrial flowering plant, because of the colourful appearance of many. A typical sea anemone is a single polyp attached to a hard surface by its base, but some species live in soft sediment and a few float near the surface of the water.

What is the difference between polyp and medusa?

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.

Are sponges polyps?


Corals are marine organisms from the class Anthozoa and exist as small sea anemone-like polyps, typically in colonies of many identical individuals. The group includes the important reef builders that are found in tropical oceans. Sponges are animals of the phylum Porifera.

What is the function of feeding polyps?

Most corals feed at night. When capturing food particles, corals feed in a manner similar to sea anemones. Polyps extend their tentacles to capture prey, first stinging them with toxic nematocyst cells, then drawing them toward their mouths.

What do reproductive polyps produce?

The reproductive polyps develop buds, which when released form small free-living medusae (ie. small jelly fish). The medusae produce sperm and eggs and the fertilized eggs develop into free swimming larvae called planula.

What are three functions of a cnidarians Gastrovascular cavity?

What are the three functions of the gastrovascular cavity of a sea anemone? Digestion, distribution of nutrients throughout the body, and it can serve as a hydrostatic skeleton.

How are cnidarians classified?

Cnidarians are classified into four main groups: non-moving (sessile) Anthozoa (sea anemones, corals, sea pens); Cubozoa (box jellies);swimming Scyphozoa (jellyfish); and Hydrozoa, a broad group that includes all the freshwater cnidarians as well as many marine forms. Cnidaria have no organs like hearts or lungs.

Are polyps fish?


A polyp, also called an adenoma, is a mushroom-shaped tag of tissue that grows in the colon and can develop into colorectal cancer. The idea researchers have been pursuing is that the omega-3 fats in fish might have an anti-inflammatory effect, similar to aspirin, that could prevent the development of polyps.

How does food get into a cnidarian?

Cnidarians are carnivores, and some can also consume plant matter. They catch their food using their nematocysts or through filter feeding. Cnidarians digest their food using a primitive digestive system that contains no organs--they have a mouth (which also serves as the anus) and a gastrovascular cavity.

What are Cnidae and nematocysts?

Introduction. A Cnidocyte is also called as a cnidoblast or a nematocyte. A cnidocyte is an explosive cell having within it a giant secretory organelle (organ) called cnida which is a characteristic of the phylum Cnidaria. A Nematocyst is a specialized sub-cellular organelle (part of the cell) present in cnidocyte.