Induction of metamorphosis in the pediveliger larvae of the mussel mytilus galloprovincialis by neuroactive compounds

Abstract

Effects of neuroactive compounds on the metamorphosis of pediveliger larvae of the mussel Mytilus galloprovincialis have been examined. Among the compounds tested, carbamylcholine and epinephrine both induced high percentage metamorphosis to post larvae. Norepinephrine, L-DOPA and serotonin were less active inducers of metamorphosis. These inducers were found effective at 10 μM, except for serotonin which significantly induced metamorphosis at 100 μM. By contrast, L-DOPA exhibited toxicity at 100 μM. Efficacy of the inducers varied with exposure time. Epinephrine was a fast acting inducer of metamorphosis; 3 h exposure efficiently yielded maximum results. On the other hand, efficacy of carbamylcholine as inducer increased with longer exposure time. Among the 5 vertebrate adrenergic antagonists tested, phentolamine significantly blocked the metamorphosis inducing activity of epinephrine. However, WB4104, yohimbine and propranolol all exhibited agonist activity in the absence of epinephrine. These results suggest that use of neuroactive compounds may provide an effective and inexpensive method to control settlement and metamorphosis of mussels.