Scapharca broughtonii larvae were treated with catecholamines to test the ability of these drugs to induce metamorphosis. L-DOPA(10-4 mol/L) can promote larval metamorphosis significantly, while dopamine does not induce metamorphosis. High concentrations of L-DOPA and dopamine are toxic to the larvae. Epinephrine and norepinephrine can increase the metamorphosis rate obviously and cause no harm to the larvae Catecholamines are useful for inducing metamorphosis of Scapharca broughtonii lasvae into commercial spats.