Asterias rubens (Echinodermata, Asteroida, Forcipulatida, Asteridae), dipleurula larva, hight 360 µm, Helgoland 04.2015. 1:26 min. Asteroida pass dipleurula, bipinnaria and brachiolaria stages before they change their whole construction during metamorphosis. Before the dipleurula is formed gastrulation takes place. In this coelogastrula an invagination of the vegetative pole forms the gut which develops a pair of coelomic cavities from which pairs of axo-, hydro, and somatocoels differentiate. The bipinnaria develops continuously from the dipleurula and the appearance of gut and coelomic structures can be observed in the complete transparent larvae. Video can be used for teaching.