Population Dynamics and Secondary Production of Owenia fusiformis Delle Chiaje (Polychaeta Oweniidae) along the Coasts of Emilia-Romagna (Northern Adriatic, Mediterranean Sea)

摘要: The population structure and dynamics of O. fusiformis have been studied for one annual cycle along the coasts Emilia-Romagna (Italy). Five seasonal samplings were carried out two transects differently influenced by Po river outflow, at depth 3,8 12 m, using a 0.06 m2 Van Veen grab. Secondary production has evaluated according to increment weight method. Densities biomass values higher 8 m in both considered localities, probably due lower mud content sediment. pattern size-frequency histograms suggests an estimated life-span least years. growth rate youngest individuals was 3 depth, hydrodynamic levels shallower waters. Total ranged from minimum 0.12 g m−2 y−1 off Cesenatico, maximum 14.78 Porto Garibaldi.