Effects of bacterial films on attachment of barnacle ( Balanus improvisus Darwin) larvae: laboratory and field studies

Abstract

The influence of surface-associated bacteria and extracellular materials (ECM) produced by the bacteria during culturing on attachment (settlement) of Balanus improvisus (Darwin) cyprids was examined. The effects of three species of gram-negative bacteria, Deleya marina Corbel et al., Baumann et al., Alteromonas macleodii Baumann et al., and Pseudomonas fluorescens Migula, on attachment of barnacle cyprids were tested in week-long laboratory assays. Cells and ECM of each bacterial species decreased attachment of cyprids to polystyrene surfaces and increased attachment of cyprids to glass, compared to control untreated surfaces. The effect of D. marina on settlement of larvae onto polystyrene was also examined in field assays. In contrast to results of laboratory assays, greater attachment of B. improvisus cyprids in the field occurred on polystyrene with adsorbed ECM than on untreated surfaces. In addition, bryozoan larvae settled in greater numbers on polystyrene surfaces to which D. marina cells were attached.