What are the parts of a starfish?

1. Central Disk: The central disk is the central body of the starfish from which the arms radiate. It contains the vital organs and the mouth of the starfish.

2. Arms: Starfish typically have five arms, although some species may have more or fewer. The arms are flexible and serve various functions, including locomotion, feeding, and sensing the environment.

3. Tube Feet: Tube feet are small, muscular projections located on the underside of the arms. Each tube foot ends in a suction cup that allows the starfish to attach to surfaces and move around.

4. Madreporite: The madreporite is a small, sieve-like plate located on the aboral (upper) side of the starfish. It is part of the water vascular system and serves as an entry point for seawater, which is used for locomotion and feeding.

5. Pyloric Stomach: The pyloric stomach is a sac-like organ located in the central disk. It stores and digests food before it is passed to the digestive glands in the arms.

6. Cardiac Stomach: The cardiac stomach is a small, muscular organ located near the mouth. It helps to push food into the pyloric stomach.

7. Gonads: Starfish have multiple gonads, which are reproductive organs located in the arms. Each arm contains a pair of gonads, and they produce either sperm or eggs, depending on the sex of the starfish.

8. Papulae: Papulae are small, thin-walled projections that cover the surface of the starfish. They are involved in respiration, exchanging gases with the surrounding water.

9. Spines: Some starfish species have spines or bumps on their aboral surface. These spines can vary in size and shape and may serve for protection or camouflage.