Abstract
Surface colonization by invertebrates can be stimulated or inhibited by cues produced by biofilms, conspecifics or other macroorganisms. To study the effects of living substrata on the attachment of the brown mussel, Perna perna, two different approaches were employed: (1) mussels were distributed in sets of Petri dishes consisting of one sterile set (controls), three sets in which marine biofilms were allowed to develop in aquaria for 1, 7 or 15 days and another set that had been immersed in a natural marine environment for 1-day. There was no significant effect of biofilms on attachment, suggesting that neither age nor the source of the biofilm influenced attachment. (2) Mussels were suspended over PVC panels (controls) and over panels on which Balanus trigonus (Crustacea), Schizoporella errata (Bryozoa), Symplegma rubra or Didemnum speciosum (Ascidiacea) were present. Attachment was significantly higher on the controls and on B. trigonus than on colonial taxa such as S. rubra, S. errata and D. speciosum, probably due to antifouling defenses of these species. The results show that the composition of the biological substratum is an important factor affecting mussel behavior.
Acknowledgements
The authors thank BL Antunes for the use of panels where cultures of the different species were available and the staff of the Instituto de Estudos do Mar Alte. Paulo Moreira (IEAPM – Brazilian Navy) for support during field work. Thanks are also due to Dr Fabio B Pitombo for barnacle identification. RCP and BAPG thank CNPq for Research Productivity fellowships and FAPERJ for Scientist of the State grants. GA benefited from a FAPERJ scholarship. The manuscript greatly benefited from comments of three anonymous reviewers.