Starfish Structures

The starfish belongs to the phylum Echinodermata (means spiky skin in Latin).  The have five rays or arms and are radially symmetrical as adults. The sharp spines on their dorsal side makes them an unfavorable food for most predators except for a few including king crabs and gulls that eat these spiny sea creatures.

Vental view of starfish. The mouth of the starfish is located centrally and opens into the central stomach.

Starfish have a very simple visual system at the tip of the rays called eye spots. These light sensitive epithelial cells give the starfish the ability to distinguish between light and dark.