1. Sponges
Sponges live in water. They grow in many shapes, sizes, and colors. Some have radial symmetry, but most are asymmetrical.

2. Sessile
Adult sponges live in one place- they are sessile. They are covered with pores and belong to the phylum Porifera.

3. Filter Feeder
Sponges are filter feeders. They have collar cells inside that help filter sea water so the sponge can eat, breath, and excrete waste products.

4. Sponge Reproduction
Sponges reproduce asexually by budding or regeneration. Sponges can also reproduce sexually. They are hermaphrodites, producing both sperm and eggs. Sperm are released in the water and carried by currents to other sponges.
This barrel sponge is spawning.

5. Cnidarians
Cnidaria is Latin for “stinging cells”. There are many different groups of cnidarians: the hydra, the jellyfish, the corals, and the sea anemones.

6. About Cnidarians Most live in saltwater Radial symmetry
2 cell layers arranged into tissues
Digestive cavity where food is broken down
Most have tentacles covered with stinging cells that surround the mouth
2 body plans- polyp and medusa

7. Polyp
The polyp is shaped like a vase and is usually sessile. They hydra is an example of a polyp form.
Hydra

8. Medusa
The medusa is bell-shaped and free-swimming. The jellyfish is an example of the medusa form. Some cnidarians go through both polyp and medusa stages during their life cycles.

9. Cnidarian Reproduction
Cnidarians reproduce both asexually and sexually.
Polyps (like this hydra) reproduce by budding. They can also reproduce sexually by producing either eggs or sperm. Medusa have an asexual stage and a sexual stage of reproduction. Fertilized eggs develop into larvae which grow into polyps. Young medusa then bud and the cycle starts again.

10. Coral
Coral reefs are found in warm waters of tropical seas. Sea anemones often attach themselves to dead coral. The largest coral reef system in the world is the Great Barrier Reef of Australia.
Coral reefs protect beaches and shorelines from damaging ocean waves.