Invertebrate Zoology: Phylum Porifera and Platyhelminthes

Phylum Porifera

• Porifera means "pore-bearing" in Latin
• Characterized by:
  • Perforated body walls
  • Simple, multicellular structure
  • No true tissues or organs
  • Filter feeders
• Examples:
  • Sponges
  • Sea sponges
• Habitat:
  • Marine environments
  • Freshwater environments

Phylum Platyhelminthes

• Flatworms
• Characterized by:
  • Bilateral symmetry
  • Flat, ribbon-like body
  • No internal body cavity
  • Simple nervous system
• Examples:
  • Tapeworms
  • Liver flukes
  • Free-living flatworms
• Habitat:
  • Freshwater environments
  • Marine environments
  • Terrestrial environments

Phylum Annelida

• Segmented worms
• Characterized by:
  • Bilateral symmetry
  • Segmented body
  • True body cavity (coelom)
  • Closed circulatory system
• Examples:
  • Earthworms
  • Leeches
  • Marine worms
• Habitat:
  • Freshwater environments
  • Marine environments
  • Terrestrial environments

Phylum Arthropoda

• Jointed-legged animals
• Characterized by:
  • Bilateral symmetry
  • Jointed appendages (legs, antennae)
  • Exoskeleton (made of chitin)
  • Segmented body
• Examples:
  • Insects (beetles, flies, bees)
  • Crustaceans (crabs, lobsters, shrimp)
  • Arachnids (spiders, scorpions)
  • Centipedes
• Habitat:
  • Terrestrial environments
  • Freshwater environments
  • Marine environments

Phylum Chordata

• Animals with a notochord (a flexible, rod-like structure)
• Characterized by:
  • Bilateral symmetry
  • Notochord (present in embryonic stage)
  • Dorsal hollow nerve cord
  • Pharyngeal slits
• Examples:
  • Vertebrates (fish, amphibians, reptiles, birds, mammals)
  • Invertebrates (tunicates, lancelets)
• Habitat:
  • Freshwater environments
  • Marine environments
  • Terrestrial environments

Phylum Porifera

• Characterized by perforated body walls, simple multicellular structure, and no true tissues or organs
• Filter feeders, with pores allowing water to flow through their bodies
• Found in marine and freshwater environments
• Examples include sponges and sea sponges

Phylum Platyhelminthes

• Characterized by bilateral symmetry and a flat, ribbon-like body
• Lack an internal body cavity and have a simple nervous system
• Found in freshwater, marine, and terrestrial environments
• Examples include tapeworms, liver flukes, and free-living flatworms

Phylum Annelida

• Characterized by bilateral symmetry and a segmented body with a true body cavity (coelom)
• Have a closed circulatory system and a simple nervous system
• Found in freshwater, marine, and terrestrial environments
• Examples include earthworms, leeches, and marine worms

Phylum Arthropoda

• Characterized by bilateral symmetry, jointed appendages, and an exoskeleton made of chitin
• Have a segmented body and a complex nervous system
• Found in terrestrial, freshwater, and marine environments
• Examples include insects, crustaceans, arachnids, and centipedes

Phylum Chordata

• Characterized by bilateral symmetry, a notochord (present in embryonic stage), and a dorsal hollow nerve cord
• Pharyngeal slits are present in embryonic stage
• Found in freshwater, marine, and terrestrial environments
• Examples include vertebrates (fish, amphibians, reptiles, birds, mammals) and invertebrates (tunicates, lancelets)