Menu Close

Is Cnidaria a protozoa?

Is Cnidaria a protozoa?

Phylum : Protozoa This phylum includes a great diversity of small, microscopic organ-isms. These are single celled eukaryotes. Their locomotion happens using pseudopodia, cilia or flagella.

What do cnidarians have in common?

Cnidarians share several basic characteristics. All Cnidaria are aquatic, mostly marine, organisms. They all have tentacles with stinging cells called nematocysts that they use to capture food. Cnidarians only have two body layers, the ectoderm and endoderm, separated by a jelly-like layer called the mesoglea.

What are cnidarians related to?

cnidarian, also called coelenterate, any member of the phylum Cnidaria (Coelenterata), a group made up of more than 9,000 living species. Mostly marine animals, the cnidarians include the corals, hydras, jellyfish, Portuguese men-of-war, sea anemones, sea pens, sea whips, and sea fans.

What are three characteristics that all cnidarians have in common?

What are three characteristics that all cnidarian have in common? Cnidarians have an epidermis, gastrodermis, mesoglea, gastrovascular activity and tentacles. Also, they have cnidocytes and a nervous system composed of diffuse web of interconnected nerve cells called a nerve net.

Are cnidarians carnivores?

All cnidarians are carnivores. Most use their cnidae and associated toxin to capture food, although none is known actually to pursue prey. Sessile polyps depend for food on organisms that come into contact with their tentacles.

How do cnidarians differ from all other animals?

Cnidarians are distinguished from all other animals by having cnidocytes that fire harpoon like structures and are usually used mainly to capture prey. In some species, cnidocytes can also be used as anchors.

How are echinoderms and cnidarians similar?

What is similar about echinoderms and cnidarians? Cnidarians and echinoderms have radial symmetry; mollusks have bilateral symmetry. Cnidarians have no body cavity or cephalization; mollusks and echinoderms have a true coelom and cephalization.

Do cnidarians have tissues?

All cnidarians have two tissue layers. The outer layer is called the epidermis, whereas the inner layer is called the gastrodermis and lines the digestive cavity. Between these two layers is a non-living, jelly-like mesoglea.

What are the two body forms of cnidarians How are these similar How are they different?

There are two major body forms among the Cnidaria – the polyp and the medusa. Sea anemones and corals have the polyp form, while jellyfish are typical medusae. When you look at them, you can see that these body forms are the same except that one is upside down. Cnidaria have no organs like hearts or lungs.

What are five characteristics of cnidarians?

The five main characteristics of cnidarians are:

  • Radial symmetry.
  • Diploblastic animals.
  • Tissue level of organisation.
  • Presence of cnidoblasts with stinging nematocysts on the tentacles.
  • Polymorphism and have two body forms, i.e. polyp and medusa.

What do cnidarians look like?

Cnidarians are water animals that have a simple, usually symmetrical, body with a mouth opening. Stinging cells on tentacles around the mouth catch prey. Cnidarians are either bell-shaped and mobile, like the jellyfish, or tubes anchored to one spot, like coral and sea anemones.

In what ways do cnidarians differ from sponges?

Sponges vs Cnidarians One interesting difference between sponges and cnidarians is that sponges lack tissue while cnidarians have tissues but not the organ systems. Sponges and Cnidarians are very primitive acoelomic invertebrates with very simple body structures. Both organisms are found in aquatic ecosystems.