1. Phylum Cnidaria
[ni’ der ee uh]

2. Characteristics of Cnidarians
Radial Symmetry

3. Characteristics of Cnidarians
Sessile

4. Characteristics of Cnidarians
. . .and Motile

5. Characteristics of Cnidarians
Tissues- cells specialized for different purposes.

6. Characteristics of Cnidarians
Gastrovascular cavity- digestive cavity with one opening.

7. Characteristics of Cnidarians
Nervous System
Nerve Net- No brain

8. Characteristics of Cnidarians
Things Cnidarians don’t have:
Brain- or “central nervous system”
Circulatory System- No heart, no blood
Excretory Organs
Respiratory- no gills or lungs
Skeletal System

9. Characteristics of Cnidarians
Cnidocytes- Stinging cells
Poisonous
Use Pressure
Automatic

10. Characteristics of Cnidarians

11. Cnidarian Reproduction

12. Cnidarian Reproduction
2 body forms in lifecycle
Medusa- motile; produce eggs or sperm.
Polyp- sessile; reproduces asexually to form new medusae
Both forms are diploid

13. Cnidarian Reproduction
Cnidarian Larvae = Planula

14. Cnidarian Reproduction
Polyp budding
Asexual

15. Cnidarian Reproduction
Polyps

16. Cnidarian Diversity
Anthozoa- Corals and Anenomes

17. Cnidarian Diversity
Scyphozoa- True Jellyfish

18. Cnidarian Diversity
Hydrozoa- Hydroids, Portugese Man-o-war
Colonial