pearl oyster the common name of Pinctada maxima and P. margaritifera, edible bivalves of SE Asia. They are not true oysters, but there is a general resemblance. P. maxima may measure 30 cm (1') and has shells which are at first yellow but later purplish-black. The inside is of a pearly brilliance; and there may be an actual pearl inside as well. P. margaritifera is dark inside.
The meat of the pearl oyster is delicious, and expensive.
© the Estate of Alan Davidson 1999, 2006, 2014 © in the Editor’s contribution to the second and third editions, Oxford University Press 2006, 2014.