The seasonal dynamics of six species of Dorvilleidae (Polychaeta) in the harbour of La Spezia (Italy)

In the harbour of La Spezia (Italy) six polychaete species belonging to the family Dorvilleidae are present. The population dynamics of Dillophilus gyrociliatus, Ophryotrocha hartmanni, O. japonica, O. labrotfica, O. puerilis and Schistotnerin-gos rudolphii has been studied from August 2002 to August 2003. The density of each species was considerably different and during the year there was a species succession that alternated in dominating the community. The role of the life-history characteristics of each species and environmental conditions in determining the Population dynamics arc discussed