INTERNAL ANATOMY

Dissection of Asterias rubens
1 - Pyloric stomach 2 - Intestine and anus 3 - Rectal sac 4 - Stone canal 5 - Madreporite 6 - Pyloric caecum 7 - Digestive glands 8 - Cardiac stomach 9 - Gonad 10 - Radial canal 11 - Tube feet.

in the internal of starfish, it possess a hydraulic water vascular system and it has many projection called as tube feet. this tube feet can emerge through openings in the endoskeleton and externally expressed through the open groves along the bottom in each of arms.
Starfish, have DIGESTIVE SYSTEM & NERVOUS SYSTEM.