The effect of scales of surface roughness on the settlement of barnacle(Semibalanus balanoides)cyprids

Abstract

Previous work on the effect of surface roughness on barnacle settlement has used natural surfaces differing in aspects other than surface roughness, or simplistic manufactured surfaces. A new technique is presented which permits accurate, controlled and repeatable manufacturing of tiles with a range of complex naturalistic surfaces created from natural components. Use of this technique permits an experimental approach to be used to investigate the effects of a range of complex surfaces on barnacle settlement. Moulds with smooth (S), fine (F) (Semibalanus balanoides settlement was recorded for the next 30 tides. Settlement density was different between the tiles with decreasing settlement in the order F > M > C > S. Settlement pattern, described using Morisita's index, was different between the textures with greater aggregation on the S tiles. Nearest neighbour analysis for the first to the tenth nearest neighbours at densities up to 18 cyprids cm^‐2 generally showed aggregated settlement at low densities but random at greater densities, though there were between texture differences. The patterns identified are discussed in relation to the ecology of S. balanoides.