Echinoderm

Echinoderm

1. Gen. charac.

   • 1. All members have a calcareous skeleton.
     • 2. Spiny endoskeleton consist of plates
       • 3. Unique water-vascular system
         • 4. Pentaradial symmetry in adult
           • 5. None are parasitic

2. Class Asteroidea ( e.g starfish)

   • 1. Diversity - common along shorelines n may on rocks - some live in muddy/sandy/coral reef
     • 2. Form n F(x) - i. External feature - have a central disc w tapering arms - body flattened n flexible w pigmented n cilated epidermis - mouth in oral (underside) surface - ambulacrum run from mouth to tip of arm - usually have 5/more arm - ambulacral groove bordered by rows of tube feet