Sea Star Anatomy

External

Central

(Arms)

Endoskeleton; ossicles

Water enters water vascular system

Endoskeleton; ossicles

Extensions of water vascular system; ampullae contracts for motion

A depression which contains tube feet

Internal Anatomy of Sea Star

Digestive gland

Sea Star Anatomy Questions

1. The mouth of a sea star is located on the ____________ surface. The anus and madreporite are located on the __________ surface.– Ventral; dorsal

2. What is the function of the madreporite (sieve plate)?– Regulate water into water vascular system

Sea Star Anatomy Questions

3. What is the function of the pedicellarias?– Respiration; wave action keeping skin free of

debris4. What are the eyespots of a sea star able to

sense?– Light

5. What are the extensions of the water-vascular system called?– Tube feet

Sea Star Anatomy Questions

6. List the four functions in which tube feet aid:– Respiration; locomotion; excretion; feeding

7. What do sea stars eat?– clams, oysters and fish

8. What is the function of the skin gills?– respiration

Sea Star Anatomy Questions

9. Describe the feeding process of a sea star– push stomach through mouth and engulfs prey

and brings it back10.The mouth of a sea star is located on the

ventral surface. Why is that an adaptive advantage for the sea star?– Sea stars are carnivorous and detritus feeders;

majority of food attaches to rock, i.e. coral polyps, clams)