name the shellfish which is cultured to obtain pearl
Cultured pearl A cultured pearl is a pearl created by an oyster farmer under controlled conditions. Cultured pearls can be farmed using two very different groups of bivalve mollusk: the freshwater river mussels, and the saltwater pearl oysters.
Goldfish A relatively small member of the carp family (which also includes the Prussian carp and the crucian carp), the goldfish is native to east Asia. It was first selectively bred in China more than a thousand years ago, and several distinct breeds have since been developed. Goldfish breeds vary greatly in size, body shape, fin configuration and colouration (various combinations of white, yellow, orange, red, brown, and black are known).