The interplay of substrate nature and biofilm formation in regulating Balanus amphitrite Darwin, 1854 larval settlement Marco Faimali a, * , Francesca Garaventa a , Antonio Terlizzi b , Mariachiara Chiantore c , Riccardo Cattaneo-Vietti c a Istituto di Scienze Marine (ISMAR)-Sezione di Genova, Via De Marini 6, 16149 Genova, Italy b Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, (DiSTeBA) Laboratorio di Zoologia e Biologia Marina, Universita ` di Lecce, 73100 Lecce, Italy c Dipartimento per lo Studio del Territorio e delle sue Risorse (DipTeRis), Universita ` di Genova, Corso Europa, 26-16132 Genova, Italy Received 10 April 2003; received in revised form 18 November 2003; accepted 22 December 2003 Abstract The settlement of marine larvae is influenced by a wide range of physical and biological factors. It is still poorly known how the nature of substrate and the biofilm can interact in regulating settlement patterns of invertebrate larvae. Here we use laboratory experiments focused on settlement behaviour of the barnacle Balanus amphitrite. The aim of this work is to understand whether: (i) the nature of substratum can affect biofilm formation and its structure, (ii) the nature of substratum can affect B. amphitrite larval settlement, (iii) the age of the biofilms and the nature of substrate can interact in influencing larval settlement. Four kinds of substrata (marble, quartz, glass, and cembonit) were biofilmed under laboratory conditions for 5, 10 and 20 days at the temperature of 28 jC. Settlement response was investigated with 5-day-old cyprids. Biofilms were quantitatively and qualitatively analysed by scanning electron microscopy. The settlement of B. amphitrite larvae significantly differed among substrata; also, the patterns of development of biofilm assemblages changed with substrate. In addition, the larval attractiveness of different substrates tends to disappear with biofilm age. D 2004 Elsevier B.V. All rights reserved. Keywords: Balanus amphitrite; Biofilm; Biomineralogy; Cyprid settlement 0022-0981/$ - see front matter D 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.jembe.2003.12.019 * Corresponding author. CNR-Istituto di Scienze Marine (ISMAR), Sezione di Genova-Laboratorio di Biologia Marina, 16149 Genova, Italy. Tel.: +39-10-647-54-25; fax: +39-10-647-54-00. E-mail address: marco.faimali@ismar.cnr.it (M. Faimali). www.elsevier.com/locate/jembe Journal of Experimental Marine Biology and Ecology 306 (2004) 37 – 50