NEUROTRANSMITTERS AND SETTLEMENT IN THE CYPRIDS OF THE BARNACLE BALANUS AMPHITRITE

摘要

For sessile species that pass from a planctonic larval life to an adult sessile condition, the choice of substrate is critical for survival. Normally, the cyprids (competent stage) of barnacles settle and moult according to the water temperature, as well as by chemiotaxis and phototaxis, after a short exploratory period (Okazaki and Shizuri, 2000). The cyprid bears numerous sense organs and shows a well organised nervous system (Harrison and Sandeman, 1999). No data are yet available about the presence of neurotransmitters in the cyprid nervous system, even if different kinds of signal molecules (cAMP, adrenaline, dopamine, etc.) seem to be involved in the settlement process (Clare et al., 1994). The aim of the present work is to put in evidence which neurotransmitters are present in the larval stages of barnacles and if they are involved in the settlement process.