1. Phylum Cnidaria
Nomura Jellyfish

2. Coral
Hydra
Anemones
Jellyfish

3. Phylum Cnidaria The Facts … Body symmetry- Radial
Reproduction- Asexually and Sexually
Movement- Polyps- Stationary
Medusas- movement varies
Food- carnivores- sting their prey

4. HYDRA Chlorohydra viridissima
Hydra live in FRESHWATER. They are the only Cnidarians not to live in salt water.
I’m hungry! Where is my DAPHNIA?
This hydra is in its’ POLYP stage.
DAPHNIA – are small crustaceans (like shrimp)

5. TWO BODY PLANS
Medusa
FREE SWIMMING
Polyp
STATIONARY

6. CNIDOCYTES – OUCH! That stings!
Members of this phylum all have stinging cells to capture their prey and defend themselves called….
Cnidocytes
Cnidarians can move in very interesting ways
Hydra
Jellyfish
Anemones

7. Just how fast is a cnidocyte? …. Can you beat it?
The average reaction time for a cnidoctye to eject a barb is about 700 nanoseconds!!
seconds
One nanosecond = one second divided by one million!!!
seconds

8. The coral reef is made up of mostly Cnidarians and Poriferans.
Nemo on his way to school

9. Cnidarians have a TWO WAY digestive system
How do Cnidarian eat?
Use the CNIDOCYTES in the tentacles to stun and capture prey.
Tentacles pull prey to mouth and into body cavity.
Prey is digested in body cavity using enzymes
Whatever is not digested is spit out of the mouth. (ewwww…they eat and excrete out the same hole)
Cnidarians have a TWO WAY digestive system