2. By: Cristina Ortiz & Angie Sevilla

3. Cnidarians are part of the Phylum Cnidaria They are carnivorous animals that contain stinging tentacles Stinging cells are called cnidocytes Within each cnidocytes is a nematocyst

4. Two stages: Polyp and Medusa Polyp: Cylindrical body with arm-like tentacles Mouth points upward Medusa: Motile, bell-shaped body Mouth on the bottom Each has: Body wall that surrounds an internal space called a gastrovascular cavity The gastroderm is the inner lining of the gastrovascular cavity, where digestion takes place The epidermis is the outer layer of cells The mesoglea is a layer that lies between these two tissues

5. Polyp on the left & Medusa on the right

6. Polyps: Asexually by budding (two types) 1) Swelling on the side of an existing polyp & grows into a new polyp 2) Polyps produce tiny medusas that separate and become new individuals Sexual reprodction: External fertilization Takes place outside the female’s body Female releases eggs into the water and male releases sperm Zygote grows into a free- swimming larva Larva attaches to a hard surface and develops into a polyp Polyp buds and releases a medusa

7. Sea Anemones and Corals: Sea Anemones live at the depth of the ocean & use nematocysts to catch a variety of marine organisms Coral Polyps are colonial and grow together in large numbers, while limestone is created. Reproduce sexually and asexually Jelly Fish: Class Scyphozoa Scyphozoans means “cup animals” Live their lives primarily as medusas Can be quite large Reproduce sexually Hydras: Hydras lack a medusa stage Reproduce asexually by budding or sexually by producing eggs & sperm Get nutrition from capturing, stinging, and digesting small prey

8. Human Uses: Medicine Food Effects: Can be toxic to humans Stinging structures