King rail
This rail forages in shallow water near cover and eats mainly aquatic insects and crustaceans. It forages by probing the mud while moving around in shallow water.
Water vascular system
Ophiuroids, the group including brittle stars and basket stars, have a somewhat different water vascular system from sea stars, despite their superficially similar appearance. The madreporite is located on the underside of the animal, usually in one of the jaw plates. The stone canal runs upwards to the ring canal, typically located in a circular depression on the upper (i.e. internal) surface of the jaws. The ring canal has four polian vesicles.