Crown-of-thorns starfish substrates with their arms and, when offered a choice of substrates, tend to settle on coralline algae, which they will subsequently feed on. In the classic pattern for echinoderms, the bilaterally symmetrical larva is replaced by a pentamerously symmetrical stage at metamorphosis, with the latter's body axis bearing no relationship to that of the larva. Thus the newly metamorphosed starfish are five-armed and are 0.4–1 mm diameter. (Note the size of the tube feet relative to the size of the animal.) They feed on the thin coating layers of hard encrusting algae (coralline algae) on the undersides of dead coral
Common starfish produced a series of convulsions. In January 2013, large numbers of common starfish were washed up near Cleethorpes Pier on the east coast of England along with many razor shells. There were estimated to be four thousand starfish along the stretch of shore. The cause of this mass stranding was unknown but bad weather and storms out at sea coupled with higher than usual tides may have been to blame. During Storm Frank in the early hours of 31 December 2015 hundreds of starfish were stranded along the coast of Portsmouth, Hampshire. This is not a unique phenomenon and other