Why South Sea pearls grow so large?

Four reasons account for the reason why the size of South Sea Pearls could dwarf many of their other saltwater pearl counterparts. They are the large size of the Pinctada maxima, the size of the implanted bead, the length of time the pearl is left to grow in the oyster, and the oyster's environment. Due to the size of the oyster, it is able to accept a large bead. The gonad of the Pinctada maxima is several times larger than that of the Akoya. Because of this larger gonad, the South Sea oyster deposits nacre around the nucleus at a much quicker rate, especially in warm water, which speeds the oyster's metabolism. The South Seas are also extremely clean, and filled with plankton – the Pinctada maximal's favorite food source. The clean waters and abundant food supply also speeds the nacre production. The growth period for South Sea pearl is also substantially longer than that of the Akoya. Akoya pearls are harvested after only 9-16 months, where as South Sea pearls are harvested after a minimum of two years allowing for a larger size.