Many people are aware of the existence of oysters. There are hundreds of species, but only a few of them are well known. Only a few species produce the delicious oysters we know and love. For example, the common pear is the only oyster with a shell. Its closest relative, the black-eyed Susan, does not have a shell.
Pearl oysters, also called oysters or nookshells, are animal closely related to clams, scallops, and other mollusks known as bivalves, also called bias. Like other bivalves, they secrete a liquid that keeps their gills (or “nooks”) from drying out. Oysters have living, moving parts, including their brains and nervous tissue. The pearl oyster produces a liquid, or mussel juice, which helps maintain its gills while it grows. The mussel juice is full of vitamins and minerals essential to life.
All oysters, not just the common mussel, secrete a fluid that contains both balsam of Peru, or pearl mussel juice, and substances that help develop the distinctive shape of the bivalves. When a small, immature oyster makes the first attempt to reproduce, it releases this fluid in great amounts. This stimulates development of the first pair of sex organs – the paired fins of the male oysters – as well as development of the attachment of the paired sex organs to the bony outer shell of the oysters. Development of the first sex organ, the penis, takes approximately two to three weeks. Development of the second sex organ, the vulva, takes even longer, about six weeks.
After the oysters make their way through their reproductive phase and have spawned, their food supply (the food supply of the oysters and all their subsequent line) comes to an end. The oysters will then enter what is called a nutrition-free environment, where they can do no further growth or reproduction. At this time, the oysters begin what is called “nutrition cycling.” This is the period in which the oysters ingest and assimilate the various substances produced by both their parents and their natal shell. There is a great need for a high concentration of these substances in both oysters and their environment (both aquatic and freshwater).
One of the substances that the oysters must ingest and assimilate is zinc, since it is essential for the development of all the organisms in the ecosystem. In addition, there are many other essential nutrients in the oysters that are consumed directly by the oysters and are used by them as food and as part of their defense mechanisms. The most important of these nutrients are copper, sulfur, manganese and iron. Since the development of the oysters is not complete without these substances, the oysters must consume a steady supply of them to ensure their survival. However, while a healthy supply of these vital elements is readily available, it is virtually impossible to obtain it from eating raw oysters.
Fortunately, in order to receive all of these necessary nutrients, the oysters must be kept in a controlled environment in which their nutrient concentrations are well monitored. Fortunately, this is something that many people are able to accomplish. When you purchase your fresh oysters from a reputable waterfront fish market, you can be fairly sure that they were shipped by a team of expert professionals who took care to ensure that the oysters had been fed and were receiving all of the nutrition that they would require to maintain their health. Additionally, the seafood market is probably the only place that you will find a collection of live oysters that were allowed to grow until they reached maturity, because these farms do not allow oysters to breed with each other.
Once they reach maturity, however, the oysters must be returned to the sea bottom where their natural habitat is filled with oxygen. Unfortunately, because the oysters were unable to return to the sea bottom before their harvesting season was over, their natural oxygen supply is depleted as well. Once the oysters begin to die, they begin to oxidize and die off naturally over time. As a result, many of the beneficial elements within the oysters begin to be consumed by the oxygen deprived environment in which they exist. This begins the process of oxidation, which depletes the oxygen supply even further.
This is how a relatively small number of oysters in a mucky tank full of oxygen-deprived water can form the beginnings of what can become a massive chain reaction. Of course, the antioxidants within the oysters can’t keep pace. As more oysters die, their carcasses and accumulated toxins and debris tend to oxidize even further and deplete even more of the natural antioxidants. This process continues until the water quality reaches an unsafe level, which could lead to serious health threats such as clogged blood vessels, heart attacks, strokes, or other life threatening ailments.