1. Chapter 8
Sponges, Cnidarians

2. Review Animal Characteristics
–Animals b/c
have
characteristics
• Multicellular
• eukaryotic &
lack cell walls
• Heterotrophs

3. Phylum Porferia
• Asymmetric
• Sessile- attach to a substrate
• Color, shapes, and size vary
• Structure
– System of water canals
– Ostia-circulates water that carries nutrients in (via
spongeocoel) and out of cell (via oscula)

4. Level of Organization
• Lack Organs and
Tissues
– Do have specialized
cells
• Choanocytes (collar
cells) -flagella that
move water into body
• Pinacocytes-
protection; outer layer
• Archaeocytes-repair
and regeneration
• Body plan Evolution a.) usually in colonies-simplest
b. Fist stages of folding
– simple to complex c. Most efficient-most sponges have this
(more efficient) body plan

5. MicrocionaProlifera- red beard sponge

6. Feeding and Digestion
• Suspension and filter feeders
• Collar cells strain food from H2O
• Most food digested/stored in archaeocytes
• Undigested material/waste leaves with water
currents

7. Reproduction
• Asexual
– budding (uncommon)
• New sponge buds off existing adult
– Fragmentation
• Usually result of storms, waves, predators
• Sexual
– Hermaphrodites-can produce eggs or sperm (but not at
same time)
– Sperm is spawned into the water and enters another
sponge with eggs to fertilize
– Zooplankton larvae –spend time swimming before
settling on substrate
http://www.youtube.com/watch?v=QiFBhHR7VLI&safety_
mode=true&persist_safety_mode=1&safe=active

8. Ecological Roles
• Recycle calcium
• Compete with others for space
• Mutualistic –serve as host for other organisms
• Predator-prey: have few predators b/c don’t
taste good
– Hawksbill sea turtle
• Commercial: polish metals, bath
sponges
• Medical: used in treatment of
cancer

9. Review: Wrapping it all up
• http://www.youtube.com/watch?v=laJgUrSsO
_k&feature=related&safety_mode=true&persi
st_safety_mode=1&safe=active

10. Phylum: Cnidaria (pronounced "ny-DAIR-ee-an)
“stinging cells”

11. • Characteristics
– Radial symmetry
– Most have nerves and muscles
• 1st animals with this complexity
– Body arranged in circular pattern
• 2 different plan
– Polyp: benthic; mouth surrounded by tentacles
– Medusa: free floating
• Both have
– Epidermis
– Gastrovascular cavity
– Stinging Cells-cnida
• Used for locomotion, defense, capturing prey

12. Representative organisms
• Hydrozoans- colonial
• Scyphozoans-true jellyfish
• Anthozoans-sea anemones and corals

13. Feeding and Digestion
• Hydrozoans and Anthozoans: Suspension
feeders
– Sea anemone feed on inverts like brine shrimp
• Jellyfish
– Carnivorous feed on fish and larger inverts
• Prey is paralyzed by a toxin, drawn into
mouth, digested in Gastrovascular cavity
• Waste is forced back through mouth (meaning they poop
through their mouth!!!!)

14. Reproduction
• Variety of reproductive
strategies
– Asexual
• Polyps produces more
polyps or medusa
• Hydrozoans: pinch off
parts; fission
– Sexual
• Spawning
• Can be hermaphrodites or
separate sexes (jellyfish)
• Go though a polyp stage
and medusa stage
• http://www.youtube.com/
watch?v=06BPlLATtgc&safe
ty_mode=true&persist_saf
ety_mode=1&safe=active

15. Ecological Roles
• Harmful poisonous
• Predators- have few predators---
Why???
• Forms habitats (coral reefs most biodiverse
ecosystem)
• Mutualistic
– Sea anemone and clownfish
– Sea anemones and hermit crabs

16. Phylum: Ctenophora
• Radial symmetry
• Lack stinging cells
• Planktonic
• Transparent
• 8 rows of comb plates w/ cilia
– Locomotion
• Surface waters
• Bioluminescence
http://www.youtube.com/watch?v=icKB9EfURhQ&s
afety_mode=true&persist_safety_mode=1&safe=
active

17. • Feeding and Digestion
– Carnivore-feed on planktonic animals
– Digested in Gastrovascular cavity
• Reproduction
– Hermaphroditic
– Spawn both eggs and sperm in water column