Vollständiger Ablauf der Metamorphose bei Echinoplutei: mit der Seeigelanlage rechts, mit beidseitiger Seeigelanlage (Janusbildung), mit fehlender Seeigelanlage.

Some echinoplutei do not develop the sea urchin disc (=oral part) on the left side of the larva, as in the majority of cases, but on the right. Also there are some which develop a sea urchin disc both right and left and finally some which have non at all. The film shows the development and metamorphosis of these three mutant developments.