Chapter 8 Sponges, Cnidarians

Review Animal Characteristics

–Animals b/c have characteristics •Multicellular• eukaryotic &

lack cell walls•Heterotrophs

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)

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– simple to complex

(more efficient)

a.) usually in colonies-simplestb. Fist stages of foldingc. Most efficient-most sponges have this

body plan

Microciona Prolifera- red beard sponge

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

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

substratehttp://www.youtube.com/watch?v=QiFBhHR7VLI&safety_mode=true&persist_safety_mode=1&safe=active

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

Review: Wrapping it all up

• http://www.youtube.com/watch?v=laJgUrSsO_k&feature=related&safety_mode=true&persist_safety_mode=1&safe=active

Phylum: Cnidaria (pronounced "ny-DAIR-ee-

an) “stinging cells”

• 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

Representative organisms

• Hydrozoans- colonial • Scyphozoans-true jellyfish• Anthozoans-sea anemones and corals

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!!!!)

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&safety_mode=true&persist_safety_mode=1&safe=active

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

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&safety_mode=true&persist_safety_mode=1&safe=active

• Feeding and Digestion– Carnivore-feed on planktonic animals– Digested in Gastrovascular cavity

• Reproduction– Hermaphroditic– Spawn both eggs and sperm in water column