Is a jellyfish a medusa or polyp?
Is a jellyfish a medusa or polyp?
Body Forms Sea anemones are examples of the polyp forms, while jellyfish are examples of the medusa forms. In the current classification, the Cnidaria phylum is divided into two major groups, Anthozoa and Medusozoa, based on the structure of polyps and the existence of a medusa stage in the life cycles (Fig.
How do polyps differ from medusa’s?
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 produce either polyp or medusa by budding, while medusa produce only medusa …
What is the difference between the polyp and medusa stages of a jellyfish?
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.
How do Hydrozoan polyps generate a medusa?
Class Cubozoa and Class Hydrozoa. Cubozoans live as box-shaped medusae while Hydrozoans are true polymorphs and can be found as colonial or solitary organisms.
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. There they develop into polyps and begin to feed and grow. In spring, some of the polyps start to bud off immature jellyfish known as ephyra larvae.
Are polyps free swimming?
Polyps is free swimming and flat while medus is cylindrical and attached to the bottom of the water body.
How do hydrozoans protect themselves?
Despite their protective stinging cells, hydrozoans are prey for many types of predators. These predators then sequester the stinging cells in their body to defend them against their own predators.
Is hydrozoa polymorphic?
Some colonial hydrozoans display polymorphism of polyps, in which morphologically distinct and functionally specialized polyp types are found within the colony. In polymorphic colonies there is a division of labor between feeding and reproduction, and in some cases, defense.
What happens jellyfish polyps?
The polyps clone themselves and bud, or strobilate, into another stage of jellyfish life, called ephyra. 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.
What do jellyfish polyps eat?
plankton
Predators and Prey Jellyfish and ctenophores are carnivorous, and will eat just about anything they run into! Most jellies primarily eat plankton, tiny organisms that drift along in the water, although larger ones may also eat crustaceans, fish and even other jellyfish and comb jellies.
How does a jellyfish form a polyp colony?
The polyp feeds by drawing food into its mouth, and as it grows it begins to bud new polyps from its trunk, forming a polyp hydroid colony in which the individual polyps are linked together by feeding tubes. When the polyps reach the appropriate size (which can take several years), they begin the next stage in the jellyfish life cycle.
What kind of Bell does a medusa jellyfish have?
The free-swimming ephyra grows in size and gradually turns into an adult jellyfish (known as a medusa) possessing a smooth, translucent bell. Strauss, Bob. “The Life Cycle of a Jellyfish.”
Can a hydroid have both male and female polyps?
Hydroid colonies are usually dioecious, which means they have separate sexes—all the polyps in each colony are either male or female, but not usually both sexes in the same colony. In some species, the reproductive polyps, known as gonozooids (or “gonotheca” in thecate hydrozoans) bud off asexually produced medusae.
How are the polyps of a hydroid colony connected?
The hydroid form is usually colonial, with multiple polyps connected by tubelike hydrocauli. The hollow cavity in the middle of the polyp extends into the associated hydrocaulus, so that all the individuals of the colony are intimately connected.