Brachiolaria

Starfish of the order Paxillosida (Astropecten and Asterina) have no brachiolaria stage, with the bipinnaria developing directly into an adult.

The brachiolaria develops from the bipinnaria larva when the latter grows three short arms at the underside of its anterior end.

The larva soon sinks to the bottom, attaching itself to the substrate, firstly with the tips of the arms, and then with the sucker.

A new mouth forming on the left side of the body, which eventually becomes the lower, or oral, surface of the adult.

Once the tube feet develop from the water vascular system, the larva frees itself from the bottom.