Meeting Abstract
One salient feature key to mussel survival is their ability to rapidly create a permanent holdfast known as the byssus, a bundle of threads glued to the substrate. These threads can persist for months despite no cellular maintenance and exposure to high tensile loads, abrasion, desiccation, and bacterial attack. Threads have a collagenous core that is coated by a protective cuticle. The collagenous core is understood to be responsible for the tensile properties of mussel threads, whereas the cuticle is theorized to protect and preserve the load-bearing core. We used transmission electron tomography, atomic force microscopy, along with other techniques to investigate the cuticle ultrastructure and mechanics of several California mussel species (Mytilus californianus, Mytilus galloprovincialis, Septifer bifurcatus, and Modiolus capax). The cuticle produced by each of these species has a distinct morphology characterized by mesoscale granular inclusions (“balls”) embedded in a continuous matrix. We explored potential contributions of the various morphologies, including: arrest of crack propagation, increased wear-resistance, increased extensibility and protection against dehydration. We attempt to reconcile the structural and mechanical properties of the differing cuticles to their unique ecological niches, and thereby gain biological insights into the design of protective coatings.
