1. Chapter 26 Sponges & Cnidarians
Kingdom Animalia
Chapter 26
Sponges & Cnidarians

2. What is an Animal? Multicellular Eukaryotic Heterotrophic
Lack cell walls
Sexual reproduction
Movement (some)
Specialization (some)

3. 2 main categories of Animals
Invertebrates: lack backbone or vertebral column. 95% of animals!
Vertebrates: have a backbone of bone or cartilage. 5% of animals.

4. What animals do to Survive!
There are 7 essential functions of animals:
1)Feeding:
Herbivore = eats plants Carnivore = eats animals Omnivore = eats plants and animals Detritivore = feed on decaying organic material Filter Feeders = aquatic animals that strain food from water Parasite = lives in or on another organism (symbiotic relationship)

5. 2)Respiration: Take in O2 and give off CO2 Lungs, gills, through skin, simple diffusion
3)Circulation: Very small animals rely on diffusion Larger animals have circulatory system
4)Excretion: Primary waste product is ammonia Liquid waste

6. 5)Response: Receptor cells = sound, light, external stimuli Nerve cells => nervous system
6)Movement: Most animals are motile (can move) Muscles usually work with a skeleton
7)Reproduction: Most reproduce sexually = genetic diversity Many invertebrates can also reproduce asexually = to increase their numbers rapidly

7. Trends in Animal Evolution
More complex animals tend to have:
-high levels of cell specialization (Cells -->tissues -->organs --> organ systems)
-bilateral symmetry
-cephalization

8. Body Symmetry
With the exception of sponges, all animals exhibit some type of body symmetry.

9. Cephalization
Animals with bilateral symmetry usually display cephalization.
Concentration of nerves in the front end (head) of body.

10. Body Cavities (coelom)
Acoelomate
Pseudocoelomate
Coelomate
Fluid-filled space that forms between the digestive tract and the outer wall of the body during development
Can aid in movement and as a reservoir for transporting nutrients and wastes

11. Sponges Phylum Porifera (pore bearing) Body Plan – no symmetry
acoelomate
Filter feeding
Some specialization of cells

12. 3 Main groups of Sponges
1)soft – internal skeleton made of protein spongin
2)calcareous – skeleton made of spicules containing CaCO3.
3)silicate – skeleton made of spicules containing silica (glass)
Spicule = spike shaped structure

13. Cnidarians Phylum Cnidaria Radial symmetry Acoelomate
Have stinging tentacles
2 body forms
Medusa
polyp

15. Contain stinging cells called cnidocytes in their tentacles that contain coiled stingers called nematocysts that can shoot out & paralyze prey 

16. 3 Classes of Cnidarians
1)Class Scyphozoa: Jellyfish

17. 2)Class Hydrozoa: hydras, Portuguese man-of-war

18. 3)Class Anthozoa: sea anemones & coral