Observations of Spio decoratus (Polychaeta Spionidae) life history under laboratory conditions, with taxonomic considerations.

The life cycle of Spio decoratus Bobretzky 1871 was studied under laboratory conditions: some life history traits and morphological features were analysed and compared to those of other species belonging to the genus Spio. Spio decoratus resulted a polythelic species with continous reproduction and a life span of about 5 months. Deposition occurred within gelatinous masses and pelagic phase took 1 week.