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
Asexual reproduction in starfish fission. In Brazil, only male individuals have been found and fission takes place all the year round, though primarily in the winter. Fission seems to be correlated with certain stress factors such as particularly low tides, when many starfish may be exposed to the air. "Nepanthia belcheri" has a variable number of arms and divides by fission in a similar manner. It is a hermaphrodite, some individuals having gonads that function as testes and others gonads that function as ovaries. After fission, the gonads regress and individuals that previously had mature female gonads become masculinized, developing male-type gonads. Many larger