ZOO PT.2

• Major Animal Phyla


  • Porifera
  • Cnidaria
  • Platyhelminthes
  • Nematoda
  • Mollusca
  • Annelida
  • Arthropoda
  • Echinodermata
  • Chordata
• Porifera (Sponges)

  • Asymmetrical or Radial symmetry
  • No organs
  • Most are Marine
  • Sessile filter-feeders
  • Asexual Reproduction - Fragmentation
  • Sexual Reproduction - Hermaphrodites
• Cnidaria


  • Radial symmetry
  • Mostly Marine
  • Have Nerve Cells
  • Nematocysts - stinging tentacles
  • 2 Body Forms: Polyp and Medusa
• Platyhelminthes (Flatworms)


  • Bilateral Symmetry
  • Definite Head
  • Thin, solid body
  • Excretory and Digestive System
  • Oxygen by diffusion
  • Hermaphrodites
• Life Cycle of the Hookworm

  1. Eggs produced by female worms leave the body in the stool

  2. The eggs hatch into larvae in the soil

  3. Hookworm larvae enter the body through the skin or mouth and pass into the bloodstream

  4. The larvae travel through the bloodstream to the lungs

  5. Secretions from the lungs, which contain the larvae, are coughed up and swallowed, passing into the stomach

  6. The larvae pass into the intestines, where they mature into adult worms
• Nematoda (Roundworms)


  • Bilateral symmetry
  • Tough outer covering
  • 2 openings
  • Tube-like digestive system
  • Separate sexes
• Mollusca


  • Bilateral symmetry
  • Mostly Marine
  • 3 body parts: foot, visceral mass, mantle
  • Have: heart; digestive, excretory, and open circulatory systems; gills
  • Mostly separate sexes
• Annelida (Segmented worms)


  • Aquatic and terrestrial
  • 2 body openings
  • Have nervous, digestive, excretory, and closed circulatory systems; head, nephridia
• Arthropoda Classes


  • Arachnids
  • Crustaceans
  • Myriapods
  • Insects
• Arachnids


  • 2 pairs of mouth parts (chelicerae)
  • 8 legs
• Crustaceans


  • Aquatic except for pill bug
  • 2 pair of antennae
• Myriapods


  • Many legs
• Insects


  • 6 legs
  • 3 body sections
• Echinodermata


  • Spiny skin
  • Bilateral symmetry as larvae
  • Radial Symmetry as adult
  • Separate sexes
  • Endoskeleton
  • Marine
• Chordata (Vertebrates)


  • Notochord
  • Dorsal Nerve Cord
  • Gill slits
  • No vertebrae
• Cephalochordata (Lancelet Branchiostoma)


  • Notochord
  • Dorsal Nerve Cord
  • Gill slits
  • No vertebrae
• Chordata (Vertebrates) Classes


  • Agnatha (Jawless fish)
  • Chondrichthyes (Cartilaginous fish)
  • Osteichthyes (Bony fish)
  • Amphibia
  • Reptilia
  • Aves
  • Mammalia
• Amphibians


  • Must return to water to reproduce
  • Aquatic larvae
  • Semi-terrestrial adult
  • Moist habitat
• Reptiles


  • Dry, scaly skin
  • 3-chambered heart
  • Lays amniotic egg on land
  • Ectotherms (body temp. depends on environment)
• Birds


  • Endotherms (Internal body heat)
  • Feathers
  • Hollow bones
  • 4-chambered heart
• Mammals


  • Endotherms
  • Hair
  • Milk produced in mammary glands
  • Nurse young
  • 4-chambered heart
  • Live birth for most mammals
  • Highly developed brains