Porifera - “to bear pores”

• level of organization - multicellular w/ specialization, but no tissues
• body symmetry - asymmetrical
• alimentary structures - no extracellular digestion, only phagocytosis
  • filter feeds
• reproduction - both sexual/asexual
  • asexual reproduction - budding, gemmule release
  • sexual reproduction - amoebocytes become gametes
• spicules - crystalline skeletal structures in sponge wall
• spongocoel - central cavity in sponge
• porocytes - forms the pores in sponge
• choanocytes - flagellated cells that draw water through the pores
• not plants due to lack of photosynthesis
• Grantia - simplest sponges
  • sessile, filter-feeding
• Spongia - more complex arrangement of chambers than Grantia

Cnidaria - “stinging cells”

• level of organization - diploblastic (2 cell layers), tissues but no organs
• body symmetry - radial symmetry
• alimentary structures - 1-hole sac plan (same hole used as mouth/anus)
  • digestion in gastrovascular cavity
• cnidocytes w/ nematocysts to sting prey
• polymorphism - ability to change body shape
  • polyp - mostly stationary
  • medusa - free-swimming
• Class Hydrozoa - dominant polyp stage
  • Portuguese man-of-war (Physalia)
• Class Scyphozoa - dominant medusa stage
  • “true jellyfish”
• Class Anthozoa - no medusa stage, usually in colonies
  • corals - makes skeleton of calcium carbonate
  • Metridium - commone anemone, has tentacles sticking out like hair
• reproduction - both sexual/asexual
  • asexual reproduction - budding, fragmentation
  • sexual reproduction - medusa release sperm and eggs that become planula larva, which attaches to substrate to become polyp