Interspecies comparison of the mechanical properties and biochemical composition of byssal threads

WOS: 000397614200009PubMed ID: 28153979Several bivalve species produce byssus threads to provide attachment to substrates, with mechanical properties highly variable among species. Here, we examined the distal section of byssal threads produced by a range of bivalve species (Mytilus edulis, Mytilus trossulus, Mytilus galloprovincialis, Mytilus californianus, Pinna nobilis, Perna perna, Xenostrobus securis, Brachidontes solisianus and Isognomon bicolor) collected from different nearshore environments. Morphological and mechanical properties were measured, and biochemical analyses were performed. Multivariate redundancy analyses on mechanical properties revealed that byssal threads of M. californianus, M. galloprovincialis and P. nobilis have very distinct mechanical behaviours compared with the remaining species. Extensibility, strength and force were the main variables separating these species groups, which were highest for M. californianus and lowest for P. nobilis. Furthermore, the analysis of the amino acid composition revealed that I. bicolor and P. nobilis threads are significantly different from the other species, suggesting a different underlying structural strategy. Determination of metal contents showed that the individual concentration of inorganic elements varies, but that the dominant elements are conserved between species. Altogether, this bivalve species comparison suggests some molecular bases for the biomechanical characteristics of byssal fibres that may reflect phylogenetic limitations.Fonds de Recherche du Quebec sur la Nature et les Technologies (FRQNT) [2012-PR-145239]; Natural Sciences and Engineering Research Council of Canada (NSERC, discovery grant)Natural Sciences and Engineering Research Council of Canada [299100]; Tunisian government and Ressources Aquatiques Quebec (Ressources Aquatiques Quebec, Rimouski, Canada)This work was supported by the Fonds de Recherche du Quebec sur la Nature et les Technologies (FRQNT, team project 2012-PR-145239) and the Natural Sciences and Engineering Research Council of Canada (NSERC, discovery grant 299100 to R.T.).Z.B. would like to thank the Tunisian government and Ressources Aquatiques Quebec (Ressources Aquatiques Quebec, Rimouski, Canada) for the award of scholarships. R.T. and I.M. are members of the RAQ