Poster Presentation

Zebra and quagga mussels, freshwater bivalves of the Dreissena genus, are quickly multiplying and spreading throughout many tributaries in the northern United States and Canada. These mussels attach to substrates within the waterways using a network of protein threads called byssal fibers, which are the focus of this study.  The goal was to analyze the strength of these byssal fibers when subjected to tensile, shear, and torsional forces. In addition, a comparison of byssal fiber strength between the two different species was conducted.  In doing so, the goal was to come up with a physical explanation for the habitat preferences of zebra and quagga mussels.  The mussels were collected from the St. Lawrence River, incubated throughout the duration of the experiments, and studied using Science Workshop software.  Statistical analysis using a two-sample t-test of these data shows that there seems to be no strong difference in attachment strength based on species.  However, correlation tests suggest that a relationship between body mass and force exists for zebra mussels in the shear and tensile cases but does not for quaggas.  Further studies analyzing the difference in shell shapes between the two mussel species and the structure of the byssal fibers will supplement this data, giving explanations as to the habitat characteristics and physical limitations of the animals.