Annelida

• Annelida


  Segmented worms
• Annelida


  • Respire through their body surface
  • Well-developed circulatory and digestive system
• Body Plan


  • Coelomate and triploblastic
• Setae


  Bristle-like structures attached to the body wall
• Parapodia


  Annelids posses paired, paddle-like appendages along the body segments
• Nephridia


  Responsible for removing metabolic wastes and maintaining osmotic balance
• Ganglia and Nerve Cords


  • A ladder-like nervous system
  • Nerve cords are interconnected
  • Ganglia serve as local processing centers for sensory and motor information
• Prostomium


  A distinct head region
• Peristomium


  Body segment behind the prostomium
• Clitellum


  • Smooth midpiece that is present at sexual maturity
  • Secretes mucous during reproduction
• Reproduction


  • Internal Fertilization (Sexual, Hermaphroditic)
  • Regeneration (Asexual, Replace lost parts)
• POLYCHAETA


  • Largest annelid class
  • Marine organisms
  • Head with eyes and tentacles
  • Ex: clamworm
• CLITELLATA - Oligochaeta


  • No parapodia
  • Few setae
  • No distinct head
  • Ex: earthworm
• CLITELLATA - Hirudinea


  • Bodies with 34 segments
  • Ex: leech