Starfish Dissection

Where is it found?

Starfish are found in saltwater bodies all around the world.
What does it eat?
A starfish's diet usually consists of clams, oysters, sand dollars and mussels.
How does it breathe?
Starfish breathe through their feet since they are made of a thin tissue in which gasses can pass through easily.
Fun fact:
A starfish's mouth is located on the underside of its body while its anus is located on the upper side of its body.

Spines- to provide protection from predators

Ceolomic cavity- holds organs in place

Center dish- center of body containing mouth 

Inside each arm, locate two long digestive glands called the pyloric caeca. These make enzymes to digest food in the stomach. Cut a circular flap of skin from the central disc. (You will have to also cut around the madreporite in order to remove this flap.) Observe the stomach under the central disc. Remove the pyloric caeca from the dissected ray. Find the gonads (testes or ovaries) underneath. These may be small if the starfish is NOT in breeding season. Remove these to see the rest of the water vascular system. Cut off the tip of a ray to observe the parts of the tube feet. Find the zipper-like ridge that extends the length of the ray. The tube feet are attached to these. Locate the bulb-like top of a tube foot called the ampulla. This sac works like the top of an eyedropper to create suction. The bottom of the tube foot is a sucker. Embedded in the soft body wall are skeletal plates called ossicles.