VIMS

Oysters—how much do we actually know?

“The world is your oyster, and you are the pearl.” People say it all the time, but do they truly know what an oyster is? Do they know why we use that quote?

An oyster can stay out of water for a couple of days if the oyster stays cold. Oysters are intertidal and subtidal, sometimes you can find them on rocks next to the water or completely submerged under the water.

The anatomy of an oyster. Image courtesy of East Hampton Town Shellfish Hatchery.Oysters have an adductor muscle they flex the muscle to keep the shell closed. If the oyster senses that the environment is favorable, its adductor muscle, which is kind of like our biceps, relaxes so the shell can open. Then the oyster will start filter feeding.

The gills, mouth, and stomach are used for filter feeding. Like fish, oysters have 4 layers of gills, although unlike fish oysters don’t use their gills for breathing but for eating. The gills bring in algae particles, tiny plants that are out in the water, these particles then stick to the gills. If the oyster is happy with the algae it will move it up to its mouth. Then the mouth will push the particles to the stomach. This organ is a brownish-greenish color because of all the algae it eats.

However, in the winter, all the food disappears and the temperature levels fall. To protect themselves the oyster’s metabolism will slow down and they won’t do very much. When the water temperatures warm and the food starts becoming more abundant again, the oysters would then convert the lipids and sugar, from the fall, into gametes and endosperms.

Here at VIMS they condition oysters into spawning in the middle of winter by giving them warm water and food inside the building. Girl oysters can produce over 300 million eggs, yet you can’t tell the difference between a female and male oyster. VIMS also has the largest breeding program for Eastern oysters in the world.

They do their research in Chesapeake Bay and along the Eastern Shore and it takes place year-round. Oysters keep the environment healthy by filtering the water, eating the algae to keep the water clean and clear, but pollution to the water can kill oysters making the water dirty.

So, in all of this we have learned, the question still lies—what is the true meaning of the metaphor “the world is your oyster, and you are the pearl?” Well, everyone interprets it differently but I interpret it as, "A pearl is made from an oyster, so be the most valuable pearl you want to be out of your oyster, and don’t let anything stop you."

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