1. Phylum: Echinodermata Echinos = Spiny Derma = Skin Ata= to bear “bears spiny skin” Zoology Chapter 16

2. Phylum Echinodermata 5 Classes – Class Crinoidea Sea lilies Feather stars – Class Asteroidea Sea Stars – Class Ophiuroidea Brittle Stars – Class Echinoidea Sea Urchins (venomous) Sand Dollars – Class Holothuroidea Sea cucumbers

3. Characteristics Calcareous endoskeleton – Ossicles- “small bones” Adults with pentaradial symmetry (5 points) – Larvae with bilateral symmetry Water-vascular system

4. Composed of water-filled canals Used in – Attachment – Feeding – Locomotion – Respiration – Circulation of nutrients and wastes Extends to each arm and tube feet – Tube feet act as suction cups Contract & expand

5. Digestion Complete digestive tract Eat clams – Tube feet open shell – Stomach forced through mouth – Stomach into opening between clam’s shells – Digestive enzymes break down tissue – Sea Star sucks out predigested food Eat algae

6. Nervous System Nerve Net Nerve Ring Radial Nerves Eyespots – Sea stars on each arm

7. Regeneration & Reproduction Reproduction Mostly dioecious; but no sexes Sexual & Asexual 2 Gonads are present in each arms Regeneration Broken arms New body from broken arm Pearl Diver Story A form of Asexual Reproduction