Induction of settlement and metamorphosis of the pacific oyster, Crassostrea gigas (Thunberg), by L-DOPA and catecholamines.
Oyster larvae were treated with selected neuroactive compounds and structural analogs to test the ability of these drugs to induce settlement and metamorphosis. L-3,4-Dihydroxyphenylalanine (L-DOPA) induced both settlement (a behavioral response) and metamorphosis (a morphogenetic response). In contrast, epinephrine and norepinephrine induced metamorphosis only, without settlement. A model of natural settlement and metamorphosis is proposed which considers both exogenous environmental cues and endogenous neuroactive factors