Sponges

• Sponge attributes

  • invertebrates
  • no germ layers
  • no nervous, circulatory, digestive, and respiratory system
  • sessile
  • no symmetry
  • sexual and asexual reproduction
• spicules


  spiky, stiff, needle-like structures that support a sponge's walls
• spongin


  spongier material found in softer sponges
• collar cells


  flagellated cells that beat vigorously to create a water current in the sponge
• phagocytosis


  collar cells use this to engulf food
• osculum


  where sponges get rid of waste
• intracellular digestion


  digestion occurs inside of sponge's cells