A lot of the marine invertebrates have a planktonic larval stage, in this period the larvae are dispersed and transported by currents. When larvae mature and attain the ability to meta‐ morphose, they start looking for suitable substrates, swimming toward the bottom and ex‐ ploring the surfaces. When larvae encounter suitable substrate, they settle and metamorphose into juveniles; the survival of them is heavily dependent on where they set‐ tle. On the other hand, larval settlement and metamorphosis are influenced by local factors as salinity, temperature, light, kind of substrates, larval age, and nutritional conditions of larvae. However, one of the most important factors for settlement is the presence of chemi‐ cal tracks originated from nonspecific adults and prey organisms. Microbial films are in‐ cluded also in those kinds of tracks and induce differentially larval settlement and metamorphosis in many invertebrate species; unfortunately, these bacterial biofilm factors have not been fully characterized [1]. The first biofilm formed on a surface, the settlement and the following steps of biological colonization are known as fouling, which could be de‐ fined (since an industrial point of view) as the undesirable accumulation of dissolved chemi‐ cal compounds, microorganisms, algae and animals on submerged substrates leading to subsequent bio-deterioration of the colonized surface.