echinoderms

• echinoderm attributes

  • 3 germ layers
  • radial symmetry
  • endoskeleton made of plates called ossicles
• echinoderms

  • sea pig
  • sea lilies (sessile)
  • starfish
  • brittlestars
  • sea urchin
• water vascular system


  series of canal and tubes for circulation, moving, and capturing food
• echinoderms have tube feet that look like knobs
• madreporite: a sieve-like structure by which the entry of seawater into the vascular system of an echinoderm is controlled.
• echinoderms have a canal that extends to the center of their body
• echinoderms breathe through their tube feet
• echinoderms have nerve net
• echinoderms can regenerate their lost legs
• echinoderms have an open circulatory system
• open circulatory system: blood flows through the body in a single circuit, with no return to the heart
• echinoderms reproduce sexually and asexually, some hermaphroditic
• echinoderms perform external fertilization
• echinoderm larvae has bilateral symmetry, radial symmetry when matured