Department of Materials Science & Engineering, University of Toronto, 184 College Street, Room 140, Toronto, ON, M5S 3E4, Canada.
Department of Marine Chemistry & Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA, 02543, USA.
Sci Rep. 2021 Dec 14;11(1):23998. doi: 10.1038/s41598-021-03227-6.
Like marine mussels, freshwater zebra and quagga mussels adhere via the byssus, a proteinaceous attachment apparatus. Attachment to various surfaces allows these invasive mussels to rapidly spread, however the adhesion mechanism is not fully understood. While marine mussel adhesion mechanics has been studied at the individual byssal-strand level, freshwater mussel adhesion has only been characterized through whole-mussel detachment, without direct interspecies comparisons on different substrates. Here, adhesive strength of individual quagga and zebra mussel byssal plaques were measured on smooth substrates with varying hydrophobicity-glass, PVC, and PDMS. With increased hydrophobicity of substrates, adhesive failures occurred more frequently, and mussel adhesion strength decreased. A new failure mode termed 'footprint failure' was identified, where failure appeared to be adhesive macroscopically, but a microscopic residue remained on the surface. Zebra mussels adhered stronger and more frequently on PDMS than quagga mussels. While their adhesion strengths were similar on PVC, there were differences in the failure mode and the plaque-substrate interface ultrastructure. Comparisons with previous marine mussel studies demonstrated that freshwater mussels adhere with comparable strength despite known differences in protein composition. An improved understanding of freshwater mussel adhesion mechanics may help explain spreading dynamics and will be important in developing effective antifouling surfaces.
像海洋贻贝一样，淡水斑马贻贝和河蚬通过贻贝附着，一种蛋白质附着装置附着。附着在各种表面上可以使这些入侵贻贝迅速传播，然而，粘附机制还不完全清楚。虽然已经在单个贻贝纤维束水平上研究了海洋贻贝的粘附力学，但淡水贻贝的粘附仅通过整个贻贝脱离来表征，而没有在不同基质上进行直接的种间比较。在这里，对不同疏水性的光滑基质（玻璃、PVC 和 PDMS）上的单个斑马贻贝和河蚬贻贝附着斑的附着强度进行了测量。随着基质疏水性的增加，附着失效的频率更高，贻贝的附着强度降低。一种新的失效模式称为“足迹失效”，在这种失效模式中，失效似乎是宏观上的粘着，但表面上仍残留着微观残留物。斑马贻贝在 PDMS 上的附着强度比河蚬贻贝更强，也更频繁。虽然它们在 PVC 上的附着强度相似，但失效模式和斑块-基质界面超微结构存在差异。与以前的海洋贻贝研究的比较表明，尽管蛋白质组成存在已知差异，但淡水贻贝具有相当的附着强度。对淡水贻贝粘附力学的深入了解可能有助于解释传播动力学，并且对于开发有效的防污表面非常重要。
