Aquatic Biofouling Larvae Respond to Differences in the Mechanical Properties of the Surface on which they Settle

Surface energy has been proposed to explain the resistance of dimethyl silicones (DMS) to biofouling, but surface energy considerations alone cannot explain all the data. Because the crosslinking density of a polymer influences its elastic modulus, biofouling on DMS substrata that differ in degree of crosslinking was studied. In addition to the recently described easier release of adult macrofouling, decreasing the elastic modulus between about 0.01-0.1 kPa significantly decreased larval settlement of three groups of test organisms. It is hypothesized that larvae sense variations in elastic modulus by deformation of sensory membranes, which causes changes in mechanosensitive ion channels.