Pearlidae

Pearlidae is a family of marine bivalve molluscs, commonly known as pearl oysters. These oysters are famous for their ability to produce pearls. Unlike edible oysters, pearl oysters are primarily cultivated for their nacreous secretions, which form pearls. The family encompasses several genera, with Pinctada being the most commercially significant.

The typical habitat of pearl oysters is in tropical and subtropical waters, found attached to coral reefs, rocks, or other hard substrates. They are filter feeders, straining plankton and other organic particles from the water column. The pearl formation process begins when an irritant, such as a parasite or a piece of foreign material, enters the oyster's soft body. In response, the oyster secretes layers of nacre, a lustrous material composed of calcium carbonate and conchiolin, around the irritant. Over time, these layers build up to form a pearl.

Different species of pearl oysters produce pearls of varying colors and luster, depending on factors such as the species, water conditions, and diet. The most valuable pearls are typically white, cream, or black, with a high degree of luster and roundness. Pearl farming involves carefully introducing cultured nuclei into the oysters to stimulate pearl formation and increase the yield and quality of pearls. This practice has become a significant industry worldwide, particularly in countries like Australia, the Philippines, and Japan.