It is a classic trick of Jewish humor: If you say, “Rabbi, I don’t know that oysters have pearls,” the rabbinic advisor or Rebbetzin will interject with, “Which oysters have black spots? Which ones have shells with scales and colors like those of the sea?” In a similar vein, he will add that, “Do you know that oysters have stringy scales?” A similar exchange can be heard between a son who are brand new to the country and his father, who is already a very experienced traveler: “Rabbi, which oysters have stringy scales?”
When you hear this, your first thought may be, “Oh, those are just common old oysters!” And indeed these are also a common mistake. Even if a stringy or pearl-like pearl is not necessarily a pearl, it still can be a false impression of what a real pearl would look like. A pearl is a crystalline form of living matter that ranges in color from white to clear.
The pearl oyster lives a long and complex life cycle. The oyster starts out as a very small embryo just under water. As it grows and develops over the course of its development, it becomes an adult and hatches as a zygote. In the life cycle of a zygote, a single cell will divide into two, three, even more cells before falling off the oyster’s shell. The life cycle of the oyster begins again, starting with the division of a single cell into two, three, even more.
The life cycle of the oyster is very complicated. A pearl is formed in the end of a cell division when the zygote has completely stopped dividing and is becoming ready to die. It is actually the zygote itself that is turning into a pearl, rather than the end of any cell that might have been dividing. Once this happens, a small hole (or slit) is cut into the inside of the cell. Pieces of the live cells get dropped through this small opening, and new ones begin to grow in the hole while the original pearl remains on the outside of the opening.
Of all the different kinds of creatures in the ocean, only a few species of oysters are capable of growing and forming their own pearl. The most commonly known species in the wild is the Clibanarius rubens, which is found in waters from southwestern India up into the northern Pacific Ocean. A closely related species is the Clibanarius digueti, which is also found in the southern Indian Ocean. Both these species belong to the sub-species clibanarius, which are a very common occurrence all over the world.
Another member of the clibanarius species is the Clibanarius athermionem, which is slightly smaller than its cousin the Clibanarius rubens. This species of oyster is known to grow to an average of just over four inches in length, but it is not uncommon for them to reach six or seven inches in length. They can grow to different colors, but their most common trait is a dark gray or brown color. Their shells are also found to be oval, round or even triangle shapes.
The Clibanarius athermionem and the Clibanarius digueti both belong to the same family, which includes the sea anemone’s family. These creatures are classified as filter feeders, which means that they gather particles within their bodies and expel them as food for other living creatures. Some scientists believe that they excrete waste through their gills. Others believe that the waste is expelled through their exoskeletons.
Scientists believe that a single oyster creates a pearl when it fertilizes an egg which has already been formed within the shell. The egg and the fertilized egg to become part of a cluster called a nook. There, new oysters develop and grow until the nooks eventually turn into a large collection of pearls. Because of this process, some pearls have been said to take up to a million years to form.