Worm Phylas

Platyhelminthes, Nematoda, and Annelida by BRI :)

Characteristics of a worm

  • creeping or burrowing invertebrate
  • long, slender, soft bodies
  • no limbs
  • bilateral symmetry

Phyla Platyhelminthes

  • Characteristics: bilateral symmetry, 3 tissue layers with organs and organelles, blind gut, protonephridial excretory organs, generally dorsoventrally flattened, reproduction mostly sexually

Phyla Nematoda

  • Characteristics: bilateral symmetry, has more than 2 tissue layers and organs, psuedocoel body cavity, body processes through a gut with a sub terminal anus, covered by a complex cuticle, no circulatory system, nervous system with nerve ring

Phyla Annelida

  • Characteristics: bilateral symmetry and veriform, more than 2 cell layers and organs, body cavity is a true coelom, body had divided sections, closed circulatory system, no respiratory organs, sexual reproduction

Non Parasitic Platyhekminthes