11:57 p.m. - 2005-11-29
You put it in your mouth and swallow.
Hello everybody!
Happy Tuesday. I must say, I might dread Tuesday more than any day of the week, as I often work fourteen hours. Oh well.
After upgrading to my Diaryland Gold membership, I proceeded to upload some photos, and changed one of the entry titles to mention that. Check them out! While I was revisiting the great toad entry, I realized I had forgotten to write about oysters, as promised!
So, I will upload two pictures of these slurpy molluscs to get y'all excited, and finish my write up tomorrow!
This first picture is from the Virginia Institute of Marine Science:
And the second is a painting by George Sandstrom:
Have you ever tried raw oysters? We thought they were pretty good, and our oyster shells made the trip back to MN and now reside in my aquarium!
The eastern oyster, Crassostrea virginica, is what I'll focus on today. They're a member of the true oyster family, Ostreidae, which includes the edible oyster, wellfleet oyster and olympia oyster, all of which are edible. It seems the larger pacific and rock oysters are often eaten in the U.S. as well; these are mostly created with aquaculture. About 60% of all oysters we eat are farmed.
Eastern oysters range from two to six inches long. Their shells are made of calcium carbonate (lime) and are extruded by a skin layer called the mantle. The oyster removes this lime from the water. A main feature of of the oyster is its' "foot", which it uses to move around before cementing itself to the seafloor. Oysters are filter feeders, and therefore accept all floating debris before spitting out the dead plant and animal detritus. They like the delicious plankton, though! Unfortunately, oysters can absorb pollutants into their bodies as a result of filter feeding.
Similar to the amount of peanut brittle I have been absorbing.
Oysters prefer brackish water eight to 25 feet deep. Often they are exposed during low tide, and to prevent dehydration, hold their shells closed with their powerful adductor muscle. (This is what you have to cut or heat in order to open the shell.)
Oysters play an interesting role in history. Humans have been eating them for tens of thousands of years. In northern Florida there are huge piles of discarded oyster shells, called middens. The Timucan Native Americans of this area used steam to open the shells, and were active in the area from 1000 BC to 1700 AD. The Kentish Flats in England and the Cancale Resort in France both supported oyster beds that were documented in Roman times.
In more modern times it seems that oysters served as food for the poorest people; oyster stands were common in 18th century London. The oysters were steamed or mixed into meat pies. New York city also had stands selling inexepensive oysters. But as the oyster beds became overharvested in the 19th century, the cost of the mollusc made them available only to the wealthy.
Now, England protects oysters by forbidding their harvest until they reach five years old, and by prohibiting oyster harvest during the breeding season.
Oysters are protandric, which means they switch their gender as they age! In their first year of life, oysters most often are male! Once the water reaches 68 degrees, usually in May through August, the males release a bunch of sperm, and the females release their eggs. A female oyster can produce 100 million eggs in a breeding season! Once the oysters are two years old, they are larger and eat more food, which allows them to expend more energy to create eggs and become female.
Once the sperm fertilizes an egg, the cells divide for about six hours, and a floating throchophore is created. This little larva feeds on tiny particles for twelve to 24 hours and grows a tiny shell. This stage is called veliger larva. The veligers float around for another three weeks, eating and growing, and develop a foot, hence the name pediveliger. Now the little oyster settles to the bottom, and using excretions from the byssus gland, glues itself to a stationary object, usually an adult oyster. At this stage the little munchkin morphs into a miniature oyster, or spat. In three to five years, it is large enough to be harvested.
As you can imagine, every year oysters breed and the spat keep settling on their elders, etc etc. In the 18th century these oyster reefs were so huge that ships had to be careful to avoid them! Due to overharvesting, only 1% of this population remains.
Oysters are really important to the environment. They protect shorelines from erosion, stabilize the seabottom, create spawning areas for fish, provide habitat for other creatures and are a source of food. One oyster-eater is a shorebird called the american oyster catcher, who has a very strong, flat beak with which it pries open the oyster shells and snips their adductor muscle to get at the tender inside! At high tide, oysters are also vulnerable to attack by anemones, sea stars and sea nettles.
The question I know you've all been wanting to ask: Wendell, what about jewelry?!
It's true; eastern oysters can produce pearls. However, their quality is poor. Another family, the Pteriidae, or winged oysters, are better pearl producers. Even in three tons of pearl oysters, only three to four molluscs will contain natural pearls! $$$!Thankfully cultured pearls are just as pretty and much cheaper.
As for the aphrodisiac quality of raw oysters? Some people attribute this to the moistness of the oyster, or to its' high zinc content. I'll just have to rely on what my readers have to say on the subject!
The next time you enjoy an oyster, I hope you think of their life cycle and their role in the oceanic environment! (Also maybe nooky.)
Lemon and Cocktail sauce, Wendell.
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