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.
