Common Sea Star

Asterias forbesi

The common sea star, commonly called a starfish, has five pointed arms that vary in color from yellowish-orange to deep purple. Sea stars have:

• Small, pale-colored spines that give the it a rough texture.
• Hundreds of tiny tube feet are arranged in four rows on the pale-colored underside.
• A bright red or orange "eye" spot (called a madreporite) in the center of the body.

Sea stars grow to about 5 inches.

Where does the common sea star live?

Sea stars are a marine species and can only be found in the salty waters near the mouth of the Bay.

• They are common in shallow, rocky areas and near jetties and pilings, but can also be found in deeper waters over sandy or stony bottoms.
• Sea stars use their tiny tube feet to move over an area, but can also drift in strong currents.
• In winter, sea stars migrate to deeper waters.

What does the common sea star eat?

Sea stars feed on snails, clams, oysters, mussels and barnacles by latching their tube feet onto the prey's shells and prying them open just enough for the sea star to reach its stomach inside.

How does the common sea star reproduce?

Sea stars spawn by releasing eggs and sperm into the water, where they are fertilized.

• A female can release up to 2.5 million eggs.
• The fertilized eggs develop into free-swimming, bilaterally symmetrical larvae.
• After about three weeks, the larvae settle and metamorphose into adults with characteristic five-part radial symmetry.

Other facts about the common sea star:

• Sea stars are a relative of sea cucumbers. They are both echinoderms, which means "spiny skinned." All echinoderms have five-part radial symmetry, which is easily seen on the sea star.
• An active sea star can travel a mile in about a week.
• If one arm is lost, sea stars are able to quickly grow a new one, sometimes overcompensating and growing an extra one or two. That is why sea stars with six or more arms are occasionally found.