Embryos feed on plankton and are ciliated. After gastrulation, the embryo becomes a larva, which forms arms and grows into a juvenile sea star. The juvenile eventually matures into an adult. Many sea stars can regenerate body parts. If a detached portion of a sea star contains part of the central disc, that portion can grow into a brand new star.
Regeneration usually takes up to one year to complete.
Not a bad survival trait to have, if you ask me. A nerve ring encircles the mouth. Radial nerves extend into each arm and coordinate the functions of the tube feet. A nerve net in the body wall coordinates other parts of the sea star's brainless nervous system. Sea stars sense light with red eyespots on each arm.