What Distinguishes Cnidarians From 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.

What distinguishes cnidarians from other animals quizlet?

What are the distinguishing characteristics of phylum Cnidaria? The characteristic that most distinguishes them, is

their “cnidocytes” (whence comes the name)

. These are specialized, venomous cells, used to stun, capture, and hold prey. All cnidaria are aquatic animals, and most are marine.

What is unique about cnidarians?

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. Most Cnidarians have radial symmetry.

Which of these traits is not found in animals in phylum Cnidaria?

However, some cnidarians, such as Sea Anemones,

lack free-floating body forms

, and simply release polyps to reproduce. *Cnidarians are NOT deuterostomes. Deuterosomes include: Chordata (vertebrates, etc.); chinodermata (sea urchins, starfish, sea cucumbers); and Hemichordata (acorn worms and related);

What are 3 traits that all cnidarians have?

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.

What are two body forms of cnidarians?

They have a simple body consisting of a central gut cavity surrounded by tentacles. A jelly-like substance called mesoglea lies between the outer and inner layers of the body. 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 Coelenterates are called cnidarians?

Coelenterates are called Cnidarians

because they contain specialized cells called cnidoblasts

. They possess stinging structures called nematocysts.

Which class of cnidarians is carnivorous?

Scyphozoans

are free-swimming, polymorphic, dioecious, and carnivorous cnidarians with a prominent medusa morphology.

How do jellyfish differ from anemones?

Traits. Jellyfish are

shaped like a bell or umbrella

. Sea anemones can be brightly colored: blue, green, pink, red or a combination of colors. Both of these great animals have tentacles which contain stinging cells that inject a poision into it’s prey.

What is the purpose of the mesoglea found in animals in the phylum Cnidaria?

The mesoglea may be thinner than either of the cell layers in smaller coelenterates like a hydra or may make up the bulk of the body in larger jellyfish. The mesoglea

serves as an internal skeleton, supporting the body

. Its elastic properties help restore the shape after it is deformed by the contraction of muscles.

What are the five characteristics of cnidarians?

• Radially Symmetrical.
• Body multicellular, few tissues, some organelles.
• Body contains an internal cavity and a mouth.
• Two different forms exist, medusa and polyp.
• Reproduction is asexual or sexual.
• Has a simple net like nervous system.
• Has a distinct larval stage which is planktonic.

Are Cnidaria unicellular or multicellular?

Cnidaria,

phylum of multicellular

, radially symmetrical invertebrates (eg, hydroids, jellyfish, sea anemones, corals) dating to late Precambrian era (630-570 million years ago).

What feature of all cnidarians gives them their name?

The name Cnidaria comes from the Greek word “cnidos,” which means stinging nettle. Casually touching many cnidarians will make it clear how they got their name when their

nematocysts eject barbed threads tipped with poison

.

Do cnidarians have a brain?

Cnidaria do not have a brain or groups of nerve cells

(“ganglia”). The nervous system is a decentralized network (‘nerve net’), with one or two nets present. They do not have a head, but they have a mouth, surrounded by a crown of tentacles. The tentacles are covered with stinging cells (nematocysts).

What is difference between polyp and medusa?