Corals and Jellyfish are cnidarians, sponges are not.
Cnidarians
Yes, they are. Cnidarians include jellyfish, anemones and coral.
Jellyfish, Coral, sea anemones, sea pens
No, coral reefs are cnidarians. The reefs themselves are built by coral polyps. Coral reefs are considered cnidarians along with what you and I would commonly refer to as jellyfish. Sea anemones are also cnidarians.
Sea anemones, coral and jelly fish belong to the group of Cnidarians.
Jellyfish and Coral and sea anemones
Three examples of cnidarians are jellyfish, corals, and sea anemones.
No, sponges do not have stinging cells like those found in cnidarians (e.g., jellyfish and sea anemones). Sponges are filter feeders that rely on water flow to capture food particles, rather than using stinging cells for prey capture.
The four groups of cnidarians are Anthozoa (corals and sea anemones), Scyphozoa (true jellyfish), Cubozoa (box jellyfish), and Hydrozoa (hydras and Portuguese man o' war).
Jellyfish are cnidarians.
No, cnidarians do not have spicules. Spicules are small, needle-like structures made of calcium carbonate or silica that are found in some sponges and echinoderms for support and defense. Cnidarians, such as jellyfish and corals, have a different type of support structure called a mesoglea.
Are called "sea anemones" every coral of the order Actiniaria.