Violet-Lipped Pearl Oyster (Krobeshan Oyster)

The violet-lipped pearl oyster, more commonly known as the Krobeshan oyster, is native to the warmer waters of the islands of Krobesh. It is well-known for its production of deep violet pearls, a rare and expensive luxury item.

The pearls produced by the Krobeshan oyster are a distinctive deep violet color. They are rare and highly sought-after by the wealthy folk of Galactus. To have a piece of jewelry containing even a single violet pearl is a mark of status equal to a crown in some places. However, these pearls take a very long time to form. A single pearl takes up to three years to create, although lower-quality and smaller seed pearls take less time. This lengthy formation period contributes to the price of the pearl.

The pearl is formed when a piece of grit or another irritant makes its way into the oyster's mantle. It is slowly covered by a layer of nacre, or mother-of-pearl, which is added to over time until the pearl is harvested. Pearls can be harvested two basic ways, although only the oyster farmers of Krobesh have been able to harvest pearls without killing the oyster.

Oyster farming is practiced by placing mature oysters in large baskets to protect the oysters from natural predators, and then anchoring those baskets to a submerged anchor - usually of stone - at the ideal depth for the species. Once the oysters reach a predetermined size, they are "seeded" - a small piece of grit is carefully inserted into each oyster in order to trigger the creation of a pearl. Oysters are seeded by basket and then allowed to process the grit and form a pearl over the course of a few years. When it is determined that the pearls are ready, the basket is once more retrieved and any pearls that have developed are harvested before the oysters are returned to rest for a few cycles. The formation of a pearl is actually fairly uncommon - only around 20 of every one hundred seeded oysters produce pearls, which adds to their rarity and expense.

Pearls found in the wild can be harvested by breaking open the oyster's shell, allowing one easy access to the pearl within but not without killing the oyster. The method developed by Krobeshan oyster farmers allows one to harvest a pearl without killing the oyster, allowing it to continue living and to produce higher-quality pearls in the future. This is done by very carefully prying open the shell using tools with surgical precision, and slowly retrieving the pearl before returning the oyster to its home.

Basic Information

Anatomy

Krobeshan oysters are very large in comparison to other oyster species - they can grow up to around 9 or 10 inches across, with the largest recorded reaching 12 inches in diameter. The shell is made of layers of calcium carbonate around a quarter inch thick at the hinge, thinning out as it reaches the lip. The outside of the shell is a mottled whitish-grey and knobbly. The inside is lined with nacre, or mother-of-pearl, which is used to form pearls. Krobeshan oysters are known as violet-lipped oysters because this lining is a deep purple and can be seen at the edges of the shell while the oyster is submerged.

The shell contains a soft, fleshy body, which includes a muscular foot, a simple digestive system, gills, and a small heart. Like other bivalves, the Krobeshan oyster also has two valves, or siphons, which protrude from the shell while the oyster is submerged. These valves are used to bring water in and out of the shell, allowing the oyster to breathe. Any food particles that enter with the water are filtered by the gills and used to feed to oyster.

Genetics and Reproduction

Krobeshan oysters reproduce by releasing sperm and eggs from their gonads into the water, where they make contact with other gametes and fertilize externally. Oyster farmers have devised ways to collect these fertilized eggs or to keep the gametes from dispersing, in order to control where the offspring go.

Growth Rate & Stages

After the egg is fertilized, it develops for about seven days before hatching into larvae. These larvae feed on microscopic plankton for about seven more days before they settle on the ocean floor, where they undergo metamorphosis and begin formation of their hinged shells. After the shell has been initially formed, it continues to grow by adding a line of material to the lip of the shell. This growth occurs once per cycle for the first year or so of life, and then continues at a slower rate of once per year until the oyster's death.

Ecology and Habitats

Krobeshan oysters prefer warm, tropical saltwater. They tend to live in relatively shallow waters along the coast, up to about thirty feet deep. They are filter feeders, and often settle in areas where there is a lot of planktonic activity or small sea life that they can eat, particularly in coral reefs. They also live in rocky areas where they can attach themselves to the rock to keep themselves stationary in the rolling waves of the coastal waters. Krobeshan oysters are a good source of food for oceanic predators like starfish and snails, which drill through the shell and eat the fleshy interior.

Additional Information

Perception and Sensory Capabilities

The Krobeshan oyster has very limited sensory organs and abilities. It mostly uses chemoreceptors to detect changes in water condition, and mechanoreceptors which warn the oyster when it has been grasped by something.

Conservation Status

The violet-lipped oyster has been bred for around three hundred years by oyster farmers off the coast of Krobesh. In the wild, it is fairly rare and considered endangered due to overfishing by those searching for natural purple pearls. However, thanks to the careful work of the Krobeshan Oyster Conservation Confederation (KOCC), captive populations are carefully tracked and recorded, and breeding is planned and supervised so that the gene pool of the captive oysters remains diverse, avoiding speciation in each farmer's population.

Geographic Distribution

• Krobesh