• First stage in the larval development of most star fish.

• Usually followed by a brachiolaria stage.

• Their movements of feeding are accomplished by the bands of cilia.

• The larva is free-living.

• When it is initially formed the entire body is covered by cilia but as it grows these become confined to a narrow band.

• In some species including the common starfish the bipinnaria stage develops directly into an adult without the brachiolaria stage.

• During its metamorphosis, bilateral symmetry is over shadowed by radial symmetry.