Assuming you know the how of opening an oyster (or any bivalve), let’s explore the why. What keeps those shells shut so tightly? Magic? Shellfishness? Or are they just shy? The answer lies in one important muscle: the abductor.

A bivalve’s abductor muscle pulls the two valves together and holds them closed, keeping out all foreign objects from particles to predators. When the muscle relaxes, the shell opens slightly, allowing water to filter through and the creature within to ingest nutrients.  

Use today’s Word of the Day: Where Do You Stand On Oyster Shooters?