Cnidarians are invertebrates such as jellyfish and corals. They belong to the phylum Cnidaria. All cnidarians are aquatic. Most of them live in the ocean. Cnidarians are a little more complex than spo...Cnidarians are invertebrates such as jellyfish and corals. They belong to the phylum Cnidaria. All cnidarians are aquatic. Most of them live in the ocean. Cnidarians are a little more complex than sponges. They have radial symmetry and tissues. There are more than 10,000 cnidarian species.
The body parts of a radially symmetrical animal are arranged around a central axis so that each part extends from the center. The tentacles contain stinging cells called cnidocytes and within each one...The body parts of a radially symmetrical animal are arranged around a central axis so that each part extends from the center. The tentacles contain stinging cells called cnidocytes and within each one is a capsule called a nematocyst, which discharges to either trap or sting the prey. The movements are like a balloon; the animal can be short and thick or long and thin. A medusa is free-floating and has the mouth and tentacles on the ventral surface.
