Effects of natural biofilms on settlement of plantigrades of the mussel Mytilus coruscus

The effect of natural biofilms on settlement of plantigrades of Mytilus coruscus was investigated in the laboratory. Plantigrades settled in response to natural biofilms, and the percentages of plantigrade settlement increased with biofilm age. The settlement-inducing activity of biofilms was positively correlated with age-related characteristics of the biofilm, such as dry weight, thickness, chlorophyll a concentration and densities of bacteria and diatoms. Cluster analysis of denaturing gradient gel electrophoresis revealed high similarity between bacterial communities in biofilms according to biofilm age, indicating that bacterial community structure may not play an important role in settlement of plantigrades in this species. Therefore, natural biofilms may be used to enhance settlement of plantigrades for the Chinese aquaculture industry.