1. Jellyfish

3. Cnidarians - "stinging creature."
Phylum Cnidarians- example: hydras, jellyfish, sea anemone, coral
Soft-bodied, carnivorous animals that have stinging tentacles
Simplest animal to have body symmetry (radial) and specialized tissues.

4. Specialized cells:
Cnidocytes- stinging cells located along tentacles used for defense and to capture prey
Nematocyst- poison filled, stinging structure in the cell that contains a tightly coiled dart
Epidermis- outer layer of skin
Mesoglea- middle gel substance
Gastroderm- inner lining of “stomach”.

5. Dorsal = upper/back side
Ventral = underside/ abdominal

6. Fun fact! They can’t sting through pantyhose

8. Life Cycle Two stages: polyp and medusa Polyp- Medusa-
cylindrical body w/ arm like tentacles
mouth points upward
sessile
Medusa-
bell shaped body w/ arm like tentacles
mouth points down
motile

9. Essential functions for Cnidarians
Feeding –
Carnivorous
Tentacles arranged in circles around their mouths
Gastrovascular Cavity- digestive chamber w/ one opening like a “stomach”
No circulation, relies on the diffusion of nutrients from “stomach”
Respiration/ Circulation/ Excretion-
diffusion

11. Essential functions for Cnidarians
Response- sensory cells sense light or gravity, no brain but a nerve net

12. Essential functions for Cnidarians
Movement
Only certain stages of life are motile
Move by jet propulsion

13. Essential functions for Cnidarians
Reproduction- both sexually and asexually
asexually- polyps (budding new polyps or medusas)
sexually- in medusa stage (external fertilization).

15. Coral

17. Coral Facts Coral has a symbiotic relationship with algae
Coral excretes waste to the algae
Algae produces sugars for coral
Algae is VERY sensitive to light, temp, pH, etc

18. Coral Facts
Coral can be used for bones transplants