LUCAS, J.M.*; WAITE, J.H.: Mussel Byssus: Tendons Redesigned as Holdfast Tethers

Mytilids produce an extraorganismic structure, the byssus, which is in essence a collection of tendons. Byssal threads are fiber reinforced composite materials composed of upwards of 80% collagen, embedded in a matrix, that function to join the mussel’s byssal retractor muscle to a hard substratum. This arrangement enables mussels to control their attachment, orientation and the load bearing tension on their byssal threads. Mytilus edulis has served as the quintessential model organism for byssal research. In order to determine the feasibility of utilizing M. galloprovincialis as a parallel model, a comparison of the structural components of byssal threads was undertaken. To fully appreciate both the similarities and differences a range of parameters was considered, including; a molecular comparison of the three byssal collagens, a morphometric comparison of thread dimensions and finally the determination of the tensile properties of the threads. Understanding the general nature of these invertebrate tendons may not only provide answers as to how mussels endure the extreme environment of the intertidal zone but may also prove to be useful as biomimetic models.