The tenacity ofElminius modestusandBalanus perforatuscyprids to bacterial films grown under different shear regimes

The tenacity of cypris larvae of the barnacles (Crustacea: Cirripedia)Balanus perforatus(Bruguiere) andElminius modestusDarwin was measured on multispecies biofilms developed under contrasting shear regimes. For both species, relatively thin, dense biofilms associated with high shear (83 s-1) afforded increased tenacity over relatively thick, less dense films associated with low shear (15 s-1). Although both species showed reduced tenacity on low-shear films compared to high-shear films,E. modestuscyprids attached as strongly to low-shear films as they did to unfilmed surfaces.Balanus perforatuscyprids, however, attached less strongly to low-shear films than to unfilmed surfaces. The results show thatB. perforatusand E.modestusmay appreciate differences in bacterial communi-ties grown under different shear conditions and highlight the potential for biofilms as one of the many cues to barnacle settlement.